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· 0 checks — Desktop Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.
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Detailed Report

Audit breakdown by category with detailed findings.

48

Performance

Insights

Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling

Why this matters

Performance issues directly impact user engagement and conversion rates.

3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.

Why this matters

Performance issues directly impact user engagement and conversion rates.

A long cache lifetime can speed up repeat visits to your page. Learn more about caching.

Why this matters

Performance issues directly impact user engagement and conversion rates.

RequestCache TTLTransfer Size
img60.ddimg.cn/2019/8/16/201908161621216406.gif0.0 ms957.6 KiB
img62.ddimg.cn/2024/9/6/2024090614302220486.gif0.0 ms231.4 KiB
static.dangdang.com/cim/imp/static/js/2.bc996403.chunk.js0.0 ms107.9 KiB
/pt-front-cms-upload-file/2025/12/18/202512181820475322.png0.0 ms101.2 KiB
backend-permanent.ddimg.cn/adsmart/2026/4/7/2026040714081075750.jpg0.0 ms100.4 KiB
backend-permanent.ddimg.cn/adsmart/2026/4/14/202604141726085600.jpg0.0 ms99.4 KiB
/Standard/Framework/Extend/hosts/js/??jquery/lazyloadDiv0...0.0 ms87.3 KiB
/pt-front-cms-upload-file/2025/12/18/2025121818204823486.png0.0 ms85.6 KiB
/pt-front-cms-upload-file/2025/12/18/2025121818204782872.png0.0 ms78.3 KiB
/pt-front-cms-upload-file/2025/12/29/2025122913031122847.jpg0.0 ms60.7 KiB
/pt-front-cms-upload-file/2026/2/12/202602121436102815.jpg0.0 ms39.1 KiB
/Standard/Framework/Extend/hosts/js/??pagetop.min.js?2026...0.0 ms38.8 KiB
static.dangdang.com/cim/public/images/kefu.png0.0 ms26.6 KiB
img63.ddimg.cn/6980a660-38bd-4629-a74e-c79c7c2db431.hpuWMccm0.0 ms21.3 KiB
img63.ddimg.cn/2024/5/22/2024052209403755540.jpg0.0 ms21.2 KiB
static.dangdang.com/cim/imp/static/js/main.173af672.chunk.js0.0 ms20.1 KiB
img60.ddimg.cn/assets/pc_image/jinggongwanganbei.png0.0 ms19.6 KiB
img63.ddimg.cn/2024/5/22/2024052209403756123.jpg0.0 ms18.9 KiB
backend-permanent.ddimg.cn/adsmart/2026/3/31/2026033118030078670.jpg0.0 ms14.8 KiB
static.ddimg.cn/js/login/LoginWindow.js?201706190.0 ms12.4 KiB
backend-permanent.ddimg.cn/adsmart/2026/3/30/2026033010030519547.jpg0.0 ms12.2 KiB
databack.dangdang.com/collect.js?202604230.0 ms12.2 KiB
backend-permanent.ddimg.cn/adsmart/2026/3/27/2026032709473280091.jpg0.0 ms12.2 KiB
backend-permanent.ddimg.cn/adsmart/2026/3/27/2026032709470169642.jpg0.0 ms11.8 KiB
click.dangdang.com/js_tracker.js?202604230.0 ms8.3 KiB
img60.ddimg.cn/upload_img/00459/home/cnnic.png0.0 ms8.2 KiB
/pt-front-cms-upload-file/2025/12/18/2025121814464873534.png0.0 ms7.4 KiB
img61.ddimg.cn/7d593c48-48f6-4fc9-85e0-7d6e10dfc2a2.hpvgUvc90.0 ms6.8 KiB
img63.ddimg.cn/upload_img/00111/home/brand_128_47.png0.0 ms6.5 KiB
img63.ddimg.cn/2019/8/30/2019083014415426253.png0.0 ms4.8 KiB
static.dangdang.com/cim/imp/static/css/main.6fc00225.chunk.css0.0 ms4.6 KiB
img63.ddimg.cn/upload_img/00459/home/head_sprite.png0.0 ms4.5 KiB
img60.ddimg.cn/assets/pc_image/pc_zxfwt.png0.0 ms4.5 KiB
img60.ddimg.cn/upload_img/00111/home/loading.gif0.0 ms4.1 KiB
a.dangdang.com/smart_new.css0.0 ms3.9 KiB
img60.ddimg.cn/upload_img/00459/home/hlwjbzx_182.png0.0 ms3.8 KiB
img60.ddimg.cn/upload_img/00111/home/home_sprite_1507.png0.0 ms3.5 KiB
img61.ddimg.cn/ddimg/1462/acc2_icon_06-1642647403.jpg0.0 ms3.4 KiB
static.dangdang.com/cim/imp/static/css/2.f1a3d200.chunk.css0.0 ms3.2 KiB
static.dangdang.com/cim/public/images/none.png0.0 ms3.1 KiB
static.dangdang.com/cim/public/images/duorou.png0.0 ms2.8 KiB
img62.ddimg.cn/upload_img/00459/home/icon_cart.png0.0 ms2.7 KiB
recosys.dangdang.com/realdata/js/index/collect.js0.0 ms2.5 KiB
static.dangdang.com/cim/public/images/pangdahai.png0.0 ms2.4 KiB
static.dangdang.com/cim/public/images/diyanye.png0.0 ms2.4 KiB
static.dangdang.com/cim/public/images/runhoutang.png0.0 ms2.4 KiB
databack.dangdang.com/store.js?202604230.0 ms2.3 KiB
static.dangdang.com/cim/cim.min.js?20190923010.0 ms2.2 KiB
static.dangdang.com/js/header2012/pagetop_accessbility.min.js?v=20230626600.0 s2.4 KiB
static.dangdang.com/css/win_login20150728.css?2017021514400.0 s3.2 KiB
/pt-front-cms-upload-file/2026/1/14/202601141054102039.png0.0 ms1.8 KiB
static.dangdang.com/cim/public/images/anquan.png0.0 ms1.8 KiB
static.dangdang.com/cim/public/images/chaozan.png0.0 ms1.8 KiB
static.dangdang.com/cim/public/images/liquan.png0.0 ms1.7 KiB
img63.ddimg.cn/upload_img/00446/111/bg_sidebar.png0.0 ms1.7 KiB
static.dangdang.com/cim/public/images/chaping_gray.png0.0 ms1.7 KiB
static.dangdang.com/cim/public/images/tucao_gray.png0.0 ms1.7 KiB
static.dangdang.com/cim/public/images/dingdan.png0.0 ms1.7 KiB
static.dangdang.com/cim/public/images/32zan_gray.png0.0 ms1.7 KiB
static.dangdang.com/cim/public/images/peisong.png0.0 ms1.7 KiB
static.dangdang.com/cim/public/images/fapiao.png0.0 ms1.7 KiB
static.dangdang.com/cim/public/images/lipinka.png0.0 ms1.6 KiB
/pt-front-cms-upload-file/2025/12/19/2025121912002032910.png0.0 ms1.6 KiB
static.dangdang.com/cim/public/images/tuikuan.png0.0 ms1.5 KiB
static.dangdang.com/cim/public/images/tuihuanhuo.png0.0 ms1.5 KiB
static.dangdang.com/cim/public/images/shixiao.png0.0 ms1.5 KiB
static.dangdang.com/cim/public/images/emojis/24.png0.0 ms1.5 KiB
static.dangdang.com/cim/public/images/emojis/20.png0.0 ms1.5 KiB
static.dangdang.com/cim/public/images/emojis/37.png0.0 ms1.4 KiB
static.dangdang.com/cim/public/images/emojis/34.png0.0 ms1.4 KiB
static.dangdang.com/cim/public/images/emojis/23.png0.0 ms1.4 KiB
static.dangdang.com/cim/public/images/emojis/19.png0.0 ms1.4 KiB
static.dangdang.com/cim/public/images/emojis/21.png0.0 ms1.4 KiB
static.dangdang.com/cim/public/images/emojis/22.png0.0 ms1.4 KiB
static.dangdang.com/cim/public/images/couhe_gray.png0.0 ms1.3 KiB
a.dangdang.com/cpx.php?position=360800010.0 ms1.3 KiB
static.dangdang.com/cim/public/images/emojis/26.png0.0 ms1.3 KiB
static.dangdang.com/cim/public/images/emojis/33.png0.0 ms1.3 KiB
static.dangdang.com/cim/public/images/emojis/36.png0.0 ms1.2 KiB
static.dangdang.com/cim/public/images/emojis/32.png0.0 ms1.2 KiB
static.dangdang.com/cim/public/images/emojis/40.png0.0 ms1.2 KiB
static.dangdang.com/cim/public/images/emojis/9.png0.0 ms1.2 KiB
static.dangdang.com/cim/public/images/emojis/41.png0.0 ms1.1 KiB
static.dangdang.com/cim/public/images/emojis/16.png0.0 ms1.1 KiB
static.dangdang.com/cim/public/images/emojis/4.png0.0 ms1.1 KiB
static.dangdang.com/cim/public/images/emojis/14.png0.0 ms1.1 KiB
static.dangdang.com/cim/public/images/emojis/10.png0.0 ms1.1 KiB
static.dangdang.com/cim/public/images/emojis/43.png0.0 ms1.1 KiB
static.dangdang.com/cim/public/images/emojis/2.png0.0 ms1.1 KiB
static.dangdang.com/cim/public/images/emojis/13.png0.0 ms1.1 KiB
static.dangdang.com/cim/public/images/emojis/7.png0.0 ms1.1 KiB
static.dangdang.com/cim/public/images/emojis/5.png0.0 ms1.0 KiB
static.dangdang.com/cim/public/images/emojis/28.png0.0 ms1.0 KiB
static.dangdang.com/cim/public/images/emojis/25.png0.0 ms1.0 KiB
static.dangdang.com/cim/public/images/emojis/8.png0.0 ms1.0 KiB
static.dangdang.com/cim/public/images/emojis/35.png0.0 ms1023 B
static.dangdang.com/cim/public/images/emojis/38.png0.0 ms1005 B
static.dangdang.com/cim/public/images/emojis/1.png0.0 ms979 B
static.dangdang.com/cim/public/images/emojis/42.png0.0 ms969 B
static.dangdang.com/cim/public/images/emojis/31.png0.0 ms966 B
static.dangdang.com/cim/public/css/cim.css0.0 ms962 B
static.dangdang.com/css/header2012/footer_150526.css?2017062614400.0 s1.4 KiB
img3.ddimg.cn/00363/doc/erweima2.png14400.0 s1.3 KiB
static.dangdang.com/cim/public/images/emojis/12.png0.0 ms921 B
static.dangdang.com/cim/public/images/emojis/3.png0.0 ms917 B
static.dangdang.com/cim/public/images/emojis/6.png0.0 ms903 B
static.dangdang.com/cim/public/images/emojis/18.png0.0 ms894 B
static.dangdang.com/cim/public/images/emojis/39.png0.0 ms874 B
static.dangdang.com/cim/public/images/emojis/30.png0.0 ms840 B
static.dangdang.com/cim/public/images/emojis/11.png0.0 ms831 B
static.dangdang.com/cim/public/images/emojis/44.png0.0 ms826 B
static.dangdang.com/cim/public/images/emojis/15.png0.0 ms823 B
static.dangdang.com/cim/public/images/emojis/29.png0.0 ms810 B
static.dangdang.com/js/login/check_snbrowse.js?20260423600.0 s879 B
static.dangdang.com/cim/public/images/emojis/17.png0.0 ms774 B
static.dangdang.com/cim/public/images/emojis/27.png0.0 ms759 B
static.dangdang.com/cim/public/images/emojis/47.png0.0 ms692 B
static.dangdang.com/cim/public/images/emojis/45.png0.0 ms657 B
/dde.php?platform=pc&type=3&url=https%253A%252F%252Fwww.d...0.0 ms394 B
/dde.php?platform=pc&type=3&url=https%253A%252F%252Fwww.d...0.0 ms394 B
/ddt.php?url=https%253A%252F%252Fwww.dangdang.com%252F&ty...0.0 ms394 B
/ddt.php?url=https%253A%252F%252Fwww.dangdang.com%252F&ty...0.0 ms393 B
/dde.php?platform=pc&type=3&url=https%253A%252F%252Fwww.d...0.0 ms392 B
static.dangdang.com/cim/public/images/emojis/46.png0.0 ms370 B
/page_tracker.php?m_id=&o_id=&region_ids=&out_refer=&refe...0.0 ms277 B
a.dangdang.com/cpx.php?position=122870.0 ms231 B
a.dangdang.com/cpt.php?pos=12284&type=00.0 ms220 B
static.dangdang.com/cim/public/images/kefu.png0.0 ms0 B

Layout shifts occur when elements move absent any user interaction. Investigate the causes of layout shifts, such as elements being added, removed, or their fonts changing as the page loads.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]
items: [map[node:map[type:text value:Total] score:0.000141] map[node:map[boundingRect:map[bottom:229 height:29 left:576 right:1275 top:200 width:699] lhId:page-1-DIV nodeLabel:欢迎光临当当，请登录成为会员 购物车0 我的订单 我的云书房 我的当当 当当拼团 企业采购 客户服务 切换无障碍 进入关怀版 path:1,HTML,1,BODY,5,DIV,0,DIV,0,DIV,1,DIV,0,DIV selector:div#tools > div.tools > div.ddnewhead_operate > div snippet:<div style="float:right"> type:node] score:0.000141 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:349 height:14 left:347 right:392 top:335 width:45] lhId:page-6-IMG nodeLabel:ul > li > span.icon_n > img path:1,HTML,1,BODY,5,DIV,4,DIV,0,UL,3,LI,1,SPAN,0,IMG selector:ul > li > span.icon_n > img snippet:<img src="https://platform-permanent.ddimg.cn/pt-front-cms-upload-file/2026/1/14/202…" alt=""> type:node]]] type:subitems]]]
headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]
items: [map[node:map[type:text value:Total] score:9.5e-05] map[node:map[boundingRect:map[bottom:697 height:20 left:640 right:770 top:677 width:130] lhId:page-2-UL nodeLabel:1 2 3 4 5 path:1,HTML,1,BODY,8,DIV,1,DIV,1,DIV,2,DIV,3,DIV,0,DIV,3,UL selector:div.con > div.home_circle_c > div#f > ul#slidelabel_nav snippet:<ul class="tab" id="slidelabel_nav" style="z-index: 10; margin-left: -33px;" dd_name="巨幕翻页"> type:node] score:8.5e-05 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:2882 height:47 left:453 right:581 top:2835 width:128] lhId:page-7-IMG nodeLabel:友情链接 path:1,HTML,1,BODY,8,DIV,3,DIV,0,DIV,2,DIV,4,DIV,2,DIV,1,DIV,0,A,0,IMG selector:div.footer_icon > div.logo4 > a > img.footer_link_img snippet:<img class="footer_link_img" src="//img63.ddimg.cn/upload_img/00111/home/brand_128_47.png" alt="友情链接"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:855 height:8 left:1155 right:1197 top:847 width:42] lhId:page-3-UL nodeLabel:1 2 3 path:1,HTML,1,BODY,8,DIV,1,DIV,1,DIV,2,DIV,4,DIV,2,DIV,2,UL selector:div.con > div.home_notice_r > div#mapid_3208532_parent_9282_10047_part_10047 > ul.mix_marquee_tab snippet:<ul class="mix_marquee_tab" style="margin-left: -18px;"> type:node] score:1e-05 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:2882 height:47 left:453 right:581 top:2835 width:128] lhId:page-7-IMG nodeLabel:友情链接 path:1,HTML,1,BODY,8,DIV,3,DIV,0,DIV,2,DIV,4,DIV,2,DIV,1,DIV,0,A,0,IMG selector:div.footer_icon > div.logo4 > a > img.footer_link_img snippet:<img class="footer_link_img" src="//img63.ddimg.cn/upload_img/00111/home/brand_128_47.png" alt="友情链接"> type:node]]] type:subitems]]]
headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]
items: [map[node:map[type:text value:Total] score:0.223607] map[node:map[boundingRect:map[bottom:2937 height:2559 left:0 right:1350 top:378 width:1350] lhId:page-4-DIV nodeLabel:图书、童书 电子书 创意文具 服饰、内衣 运动户外 孕、婴、童 家居、家纺 家具、家装 食品、茶酒 家用电器 当当礼品卡 left right 1 2 3 4… path:1,HTML,1,BODY,8,DIV selector:body > div#bd snippet:<div id="bd" name="15639" cvid="39111"> type:node] score:0.222222 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:300 height:300 left:75 right:1275 top:0 width:1200] lhId:page-0-IMG nodeLabel:div#__A_C > div.cont > a > img path:1,HTML,1,BODY,0,DIV,0,DIV,0,DIV,0,A,0,IMG selector:div#__A_C > div.cont > a > img snippet:<img src="https://backend-permanent.ddimg.cn/adsmart/2026/4/14/202604141726085600.jpg" alt=""> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:229 height:29 left:576 right:1275 top:200 width:699] lhId:page-1-DIV nodeLabel:欢迎光临当当，请登录成为会员 购物车0 我的订单 我的云书房 我的当当 当当拼团 企业采购 客户服务 切换无障碍 进入关怀版 path:1,HTML,1,BODY,5,DIV,0,DIV,0,DIV,1,DIV,0,DIV selector:div#tools > div.tools > div.ddnewhead_operate > div snippet:<div style="float:right"> type:node] score:0.001385]]
headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]
items: [map[node:map[type:text value:Total] score:0.001543] map[node:map[boundingRect:map[bottom:229 height:29 left:576 right:1275 top:200 width:699] lhId:page-1-DIV nodeLabel:欢迎光临当当，请登录成为会员 购物车0 我的订单 我的云书房 我的当当 当当拼团 企业采购 客户服务 切换无障碍 进入关怀版 path:1,HTML,1,BODY,5,DIV,0,DIV,0,DIV,1,DIV,0,DIV selector:div#tools > div.tools > div.ddnewhead_operate > div snippet:<div style="float:right"> type:node] score:0.001543]]

Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Each subpart has specific improvement strategies. Ideally, most of the LCP time should be spent on loading the resources, not within delays.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:label label:Subpart valueType:text] map[key:duration label:Duration valueType:ms]]
items: [map[duration:1601.336 label:Time to first byte subpart:timeToFirstByte] map[duration:2808.828 label:Resource load delay subpart:resourceLoadDelay] map[duration:480.355 label:Resource load duration subpart:resourceLoadDuration] map[duration:275.345 label:Element render delay subpart:elementRenderDelay]]
lhId: page-0-IMG
nodeLabel: div#__A_C > div.cont > a > img
path: 1,HTML,1,BODY,0,DIV,0,DIV,0,DIV,0,A,0,IMG
selector: div#__A_C > div.cont > a > img
snippet: <img src="https://backend-permanent.ddimg.cn/adsmart/2026/4/14/202604141726085600.jpg" alt="">

Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading

Why this matters

Performance issues directly impact user engagement and conversion rates.

lhId: page-0-IMG
nodeLabel: div#__A_C > div.cont > a > img
path: 1,HTML,1,BODY,0,DIV,0,DIV,0,DIV,0,A,0,IMG
selector: div#__A_C > div.cont > a > img
snippet: <img src="https://backend-permanent.ddimg.cn/adsmart/2026/4/14/202604141726085600.jpg" alt="">

HTTP/2 and HTTP/3 offer many benefits over HTTP/1.1, such as multiplexing. Learn more about using modern HTTP.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLProtocol
/pt-front-cms-upload-file/2025/12/19/2025121912002032910.pnghttp/1.1
/pt-front-cms-upload-file/2025/12/18/2025121814464873534.pnghttp/1.1
/pt-front-cms-upload-file/2025/12/29/2025122913031122847.jpghttp/1.1
img63.ddimg.cn/2024/5/22/2024052209403755540.jpghttp/1.1
img63.ddimg.cn/2024/5/22/2024052209403756123.jpghttp/1.1
/pt-front-cms-upload-file/2026/2/12/202602121436102815.jpghttp/1.1
img60.ddimg.cn/upload_img/00111/home/loading.gifhttp/1.1
img63.ddimg.cn/6980a660-38bd-4629-a74e-c79c7c2db431.hpuWMccmhttp/1.1
/pt-front-cms-upload-file/2025/12/18/2025121818204782872.pnghttp/1.1
/pt-front-cms-upload-file/2025/12/18/2025121818204823486.pnghttp/1.1
/pt-front-cms-upload-file/2025/12/18/202512181820475322.pnghttp/1.1
img60.ddimg.cn/assets/pc_image/jinggongwanganbei.pnghttp/1.1
img63.ddimg.cn/upload_img/00111/home/brand_128_47.pnghttp/1.1
img60.ddimg.cn/upload_img/00459/home/hlwjbzx_182.pnghttp/1.1
img60.ddimg.cn/upload_img/00459/home/cnnic.pnghttp/1.1
databack.dangdang.com/collect.js?20260423http/1.1
databack.dangdang.com/store.js?20260423http/1.1
/pt-front-cms-upload-file/2026/1/14/202601141054102039.pnghttp/1.1
img63.ddimg.cn/upload_img/00459/home/head_sprite.pnghttp/1.1
img60.ddimg.cn/upload_img/00111/home/home_sprite_1507.pnghttp/1.1
img63.ddimg.cn/upload_img/00446/111/bg_sidebar.pnghttp/1.1
img63.ddimg.cn/2019/8/30/2019083014415426253.pnghttp/1.1
/ddt.php?url=https%253A%252F%252Fwww.dangdang.com%252F&ty...http/1.1
/dde.php?platform=pc&type=3&url=https%253A%252F%252Fwww.d...http/1.1
/dde.php?platform=pc&type=3&url=https%253A%252F%252Fwww.d...http/1.1
databack.dangdang.com/proxy.html?2026422http/1.1
/ddt.php?url=https%253A%252F%252Fwww.dangdang.com%252F&ty...http/1.1
img60.ddimg.cn/2019/8/16/201908161621216406.gifhttp/1.1
img60.ddimg.cn/assets/pc_image/pc_zxfwt.pnghttp/1.1
/dde.php?platform=pc&type=3&url=https%253A%252F%252Fwww.d...http/1.1

Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.

Why this matters

Performance issues directly impact user engagement and conversion rates.

description: [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints help the browser establish a connection earlier in the page load, saving time when the first request for that origin is made. The following are the origins that the page preconnected to.
title: Preconnected origins
value: no origins were preconnected
description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.
title: Preconnect candidates

Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLResource SizeEst Savings
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img
/pt-front-cms-upload-file/2025/12/18/202512181820475322.png100.4 KiB99.2 KiB
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img
/pt-front-cms-upload-file/2025/12/18/2025121818204823486.png84.8 KiB83.7 KiB
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img
/pt-front-cms-upload-file/2025/12/18/2025121818204782872.png77.5 KiB76.3 KiB
图书 ul#slidecontent > li > a > img
backend-permanent.ddimg.cn/adsmart/2026/4/7/2026040714081075750.jpg99.9 KiB57.7 KiB
全场低至2折 div.home_notice_r > div.home_notice_r_pic > a._1 > img
/pt-front-cms-upload-file/2025/12/29/2025122913031122847.jpg59.9 KiB53.5 KiB
div#__A_C > div.cont > a > img div#__A_C > div.cont > a > img
backend-permanent.ddimg.cn/adsmart/2026/4/14/202604141726085600.jpg98.9 KiB40.3 KiB
京公网安备 11010502037644号 div.footer_copyright > div.footer_copyright > a > img
img60.ddimg.cn/assets/pc_image/jinggongwanganbei.png18.8 KiB18.7 KiB
礼品卡 ul.list_aa > li > a._1 > img
img63.ddimg.cn/2024/5/22/2024052209403755540.jpg20.4 KiB16.5 KiB
新书 ul#Cbanner > li > a > img
backend-permanent.ddimg.cn/adsmart/2026/3/31/2026033118030078670.jpg14.5 KiB9.3 KiB
49元5件 ul#Cbanner > li > a > img
backend-permanent.ddimg.cn/adsmart/2026/3/30/2026033010030519547.jpg11.9 KiB6.7 KiB
精选榜单 ul#Cbanner > li > a > img
backend-permanent.ddimg.cn/adsmart/2026/3/27/2026032709473280091.jpg11.7 KiB6.5 KiB
友情链接 div.footer_icon > div.logo6 > a > img.footer_link_img
img60.ddimg.cn/upload_img/00459/home/cnnic.png7.4 KiB6.4 KiB
今日抢购 ul#Cbanner > li > a > img
backend-permanent.ddimg.cn/adsmart/2026/3/27/2026032709470169642.jpg11.5 KiB6.3 KiB
友情链接 div.footer_icon > div.logo3 > a > img.footer_link_img
img61.ddimg.cn/7d593c48-48f6-4fc9-85e0-7d6e10dfc2a2.hpvgUvc96.0 KiB5.0 KiB
友情链接 div.footer_icon > div.logo4 > a > img.footer_link_img
img63.ddimg.cn/upload_img/00111/home/brand_128_47.png5.7 KiB4.7 KiB

Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLTransfer Size
www.dangdang.com/Standard/Framework/Extend/hosts/css/model/homemin.css?202212021.9 KiB

These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.

Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 1.9 s
URLTime Spent
dangdang.com/903 ms
www.dangdang.com/1.0 s
www.dangdang.com/0.0 ms

These are the largest layout shifts observed on the page. Each table item represents a single layout shift, and shows the element that shifted the most. Below each item are possible root causes that led to the layout shift. Some of these layout shifts may not be included in the CLS metric value due to windowing. Learn how to improve CLS

Why this matters

Performance issues directly impact user engagement and conversion rates.

ElementLayout shift score
图书、童书 电子书 创意文具 服饰、内衣 运动户外 孕、婴、童 家居、家纺 家具、家装 食品、茶酒 家用电器 当当礼品卡 left right 1 2 3 4… body > div#bd
0.222
欢迎光临当当，请登录成为会员 购物车0 我的订单 我的云书房 我的当当 当当拼团 企业采购 客户服务 切换无障碍 进入关怀版 div#tools > div.tools > div.ddnewhead_operate > div
0.002
欢迎光临当当，请登录成为会员 购物车0 我的订单 我的云书房 我的当当 当当拼团 企业采购 客户服务 切换无障碍 进入关怀版 div#tools > div.tools > div.ddnewhead_operate > div
0.001
欢迎光临当当，请登录成为会员 购物车0 我的订单 我的云书房 我的当当 当当拼团 企业采购 客户服务 切换无障碍 进入关怀版 div#tools > div.tools > div.ddnewhead_operate > div
0.000
1 2 3 4 5 div.con > div.home_circle_c > div#f > ul#slidelabel_nav
0.000
1 2 3 div.con > div.home_notice_r > div#mapid_3208532_parent_9282_10047_part_10047 > ul.mix_marquee_tab
0.000

Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

TTI

Diagnostics

Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 270 ms 81.4 KiB
URLTransfer SizeEst Savings
/Standard/Framework/Extend/hosts/js/??jquery/lazyloadDiv0...87.1 KiB48.9 KiB
static.dangdang.com/cim/imp/static/js/2.bc996403.chunk.js107.6 KiB32.5 KiB

Many navigations are performed by going back to a previous page, or forwards again. The back/forward cache (bfcache) can speed up these return navigations. Learn more about the bfcache

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failure reasonFailure type
Pages with WebSocket cannot enter back/forward cache.Pending browser support

Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 12.0 KiB
URLTransfer SizeEst Savings
.spacer{display:none} …15.1 KiB12.0 KiB

Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL
div#__A_C > div.cont > a > img div#__A_C > div.cont > a > img
backend-permanent.ddimg.cn/adsmart/2026/4/14/202604141726085600.jpg
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img
/pt-front-cms-upload-file/2025/12/18/202512181820475322.png
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img
/pt-front-cms-upload-file/2025/12/18/2025121818204782872.png
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img
/pt-front-cms-upload-file/2025/12/18/2025121818204823486.png
div.logo_line_out > div.logo_line > div.logo > img div.logo_line_out > div.logo_line > div.logo > img
/pt-front-cms-upload-file/2025/12/18/2025121814464873534.png
友情链接 div.footer_icon > div.logo3 > a > img.footer_link_img
img61.ddimg.cn/7d593c48-48f6-4fc9-85e0-7d6e10dfc2a2.hpvgUvc9
友情链接 div.footer_icon > div.logo4 > a > img.footer_link_img
img63.ddimg.cn/upload_img/00111/home/brand_128_47.png
友情链接 div.footer_icon > div.logo6 > a > img.footer_link_img
img60.ddimg.cn/upload_img/00459/home/cnnic.png
友情链接 div.footer_nav_box > div.footer_icon > div.logo7 > img.footer_link_img
img61.ddimg.cn/ddimg/1462/acc2_icon_06-1642647403.jpg
ul > li > span.icon_n > img ul > li > span.icon_n > img
/pt-front-cms-upload-file/2026/1/14/202601141054102039.png
京公网安备 11010502037644号 div.footer_copyright > div.footer_copyright > a > img
img60.ddimg.cn/assets/pc_image/jinggongwanganbei.png

More information about the performance of your application. These numbers don't directly affect the Performance score.

●Max Potential First Input Delay 70 ms
●Optimize DOM size
●Font display
●Forced reflow
●Optimize viewport for mobile
●Minify CSS
●Minify JavaScript
●Avoids enormous network payloads Total size was 2,466 KiB
●JavaScript execution time 0.3 s
●Minimizes main-thread work 0.9 s
●Avoid long main-thread tasks 2 long tasks found
●Network Requests
●Network Round Trip Times 250 ms
●Server Backend Latencies 490 ms
●Tasks
●Diagnostics
●Metrics
●Screenshot Thumbnails
●Final Screenshot
●Script Treemap Data
●Resources Summary
●Initial server response time was short Root document took 240 ms
○INP breakdown
○User Timing marks and measures
○Avoid non-composited animations
45

Accessibility

These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.

Contrast

Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
登录 div > div.ddnewhead_welcome > span#nickname > a.login_link
热搜: 警长达克比缠斗因为独特唐宋之变活着 纪念版9.9元包邮 div.logo_line_out > div.logo_line > div.search_bottom > div.search_hot
警长达克比 div.logo_line > div.search_bottom > div.search_hot > a
缠斗 div.logo_line > div.search_bottom > div.search_hot > a
因为独特 div.logo_line > div.search_bottom > div.search_hot > a
唐宋之变 div.logo_line > div.search_bottom > div.search_hot > a
活着 纪念版 div.logo_line > div.search_bottom > div.search_hot > a
9.9元包邮 div.logo_line > div.search_bottom > div.search_hot > a
高级搜索 div.logo_line_out > div.logo_line > div.search_bottom > a.search_advs
购买流程 div.footer_sort > ul > li > a.main
发票制度 div.footer_sort > ul > li > a
服务协议 div.footer_sort > ul > li > a
会员优惠 div.footer_sort > ul > li > a
网上支付 div.footer_sort > ul > li > a.main
礼品卡支付 div.footer_sort > ul > li > a
银行转账 div.footer_sort > ul > li > a
礼券支付 div.footer_sort > ul > li > a
配送服务查询 div.footer_sort > ul > li > a.main
订单状态说明 div.footer_sort > ul > li > a
自助取消订单 div.footer_sort > ul > li > a
自助修改订单 div.footer_sort > ul > li > a
当日递 div.footer_sort > ul > li > a.main
次日达 div.footer_sort > ul > li > a
订单自提 div.footer_sort > ul > li > a
验货与签收 div.footer_sort > ul > li > a
退换货服务查询 div.footer_sort > ul > li > a.main
自助申请退换货 div.footer_sort > ul > li > a
退换货进度查询 div.footer_sort > ul > li > a
退款方式和时间 div.footer_sort > ul > li > a
商家中心 div.footer_sort > ul > li > a.main
运营服务 div.footer_sort > ul > li > a
公司简介 div.footer > div.footer_nav_box > div.footer_nav > a
网站联盟 div.footer > div.footer_nav_box > div.footer_nav > a
当当招商 div.footer > div.footer_nav_box > div.footer_nav > a
机构销售 div.footer > div.footer_nav_box > div.footer_nav > a
手机当当 div.footer > div.footer_nav_box > div.footer_nav > a
官方Blog div.footer > div.footer_nav_box > div.footer_nav > a
知识产权 div.footer > div.footer_nav_box > div.footer_nav > a
热词搜索 div.footer > div.footer_nav_box > div.footer_nav > a
Copyright 2004 - 2024 当当网. All Rights Reserved div.footer_nav_box > div.footer_copyright > div.footer_copyright > span
京ICP证041189号 div.footer_nav_box > div.footer_copyright > div.footer_copyright > span
出版物经营许可证 新出发京批字第直0673号 div.footer_copyright > div.footer_copyright > a > span
食品经营许可证：JY11101050363440 div.footer_copyright > div.footer_copyright > a > span
京ICP备17043473号-1 div.footer_copyright > div.footer_copyright > a > span
京公网安备11010502037644号 div.footer_copyright > div.footer_copyright > a > span
经营许可证编号：合字B2-20160011 div.footer_copyright > div.footer_copyright > a > span
互联网药品信息服务资格证 div.footer_copyright > div.footer_copyright > a > span
互联网违法和不良信息举报电话：4001066666-5，涉未成年举报电话：4001066666-9，邮箱：jubao@dangdang.com div.footer_nav_box > div.footer_copyright > div.footer_copyright > span
jubao@dangdang.com div.footer_copyright > div.footer_copyright > span > a
北京当当科文电子商务有限公司，通信地址：北京市东城区藏经馆胡同17号1幢A103室 div.footer_nav_box > div.footer_copyright > div.footer_copyright > span
北京当当科文电子商务有限公司 div.footer_copyright > div.footer_copyright > span > a

These are opportunities to improve the legibility of your content.

Internationalization and localization

If a page doesn't specify a `lang` attribute, a screen reader assumes that the page is in the default language that the user chose when setting up the screen reader. If the page isn't actually in the default language, then the screen reader might not announce the page's text correctly. Learn more about the `lang` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
html html

These are opportunities to improve the interpretation of your content by users in different locales.

Names and labels

Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more about the `alt` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
ul.ddnewhead_operate_nav > li.ddnewhead_cart > a > img ul.ddnewhead_operate_nav > li.ddnewhead_cart > a > img
div.logo_line_out > div.logo_line > div.logo > img div.logo_line_out > div.logo_line > div.logo > img
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img

Adding discernable and accessible text to input buttons may help screen reader users understand the purpose of the input button. Learn more about input buttons.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.logo_line > div.search > form#form_search_new > input.button div.logo_line > div.search > form#form_search_new > input.button

Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users. Learn how to make links accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div#ad_bar_top_box3 > div#__A_C > div.cont > a div#ad_bar_top_box3 > div#__A_C > div.cont > a
div.logo_line > div.search > form#form_search_new > a.del-keywords div.logo_line > div.search > form#form_search_new > a.del-keywords
div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.collect div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.collect
div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.footprint div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.footprint
div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.sidebar_points div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.sidebar_points
div.sidebar > div.sidebar_b > div.sidebar_code2 > a.code2s div.sidebar > div.sidebar_b > div.sidebar_code2 > a.code2s
div#sidebar_wrap_id > div.sidebar > div.sidebar_b > a.back_top div#sidebar_wrap_id > div.sidebar > div.sidebar_b > a.back_top
div.footer > div.footer_pic_new > div.footer_ad_new_inner > a.footer_img div.footer > div.footer_pic_new > div.footer_ad_new_inner > a.footer_img
div.footer > div.footer_pic_new > div.footer_ad_new_inner > a.footer_img div.footer > div.footer_pic_new > div.footer_ad_new_inner > a.footer_img
div.footer > div.footer_pic_new > div.footer_ad_new_inner > a.footer_img div.footer > div.footer_pic_new > div.footer_ad_new_inner > a.footer_img

These are opportunities to improve the semantics of the controls in your application. This may enhance the experience for users of assistive technology, like a screen reader.

Navigation

A value greater than 0 implies an explicit navigation ordering. Although technically valid, this often creates frustrating experiences for users who rely on assistive technologies. Learn more about the `tabindex` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
新窗口打开无障碍说明页面,按Ctrl加波浪键打开导盲模式 body > a#ddchangeaccalert

These are opportunities to improve keyboard navigation in your application.

Best practices

Touch targets with sufficient size and spacing help users who may have difficulty targeting small controls to activate the targets. Learn more about touch targets.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
购买流程 div.footer_sort > ul > li > a.main
发票制度 div.footer_sort > ul > li > a
服务协议 div.footer_sort > ul > li > a
会员优惠 div.footer_sort > ul > li > a
网上支付 div.footer_sort > ul > li > a.main
礼品卡支付 div.footer_sort > ul > li > a
银行转账 div.footer_sort > ul > li > a
礼券支付 div.footer_sort > ul > li > a
配送服务查询 div.footer_sort > ul > li > a.main
订单状态说明 div.footer_sort > ul > li > a
自助取消订单 div.footer_sort > ul > li > a
自助修改订单 div.footer_sort > ul > li > a
当日递 div.footer_sort > ul > li > a.main
次日达 div.footer_sort > ul > li > a
订单自提 div.footer_sort > ul > li > a
验货与签收 div.footer_sort > ul > li > a
退换货服务查询 div.footer_sort > ul > li > a.main
自助申请退换货 div.footer_sort > ul > li > a
退换货进度查询 div.footer_sort > ul > li > a
退款方式和时间 div.footer_sort > ul > li > a
商家中心 div.footer_sort > ul > li > a.main
运营服务 div.footer_sort > ul > li > a

One main landmark helps screen reader users navigate a web page. Learn more about landmarks.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
html html

These items highlight common accessibility best practices.

○Interactive controls are keyboard focusable
○Interactive elements indicate their purpose and state
○The page has a logical tab order
○Visual order on the page follows DOM order
○User focus is not accidentally trapped in a region
○The user's focus is directed to new content added to the page
○HTML5 landmark elements are used to improve navigation
○Offscreen content is hidden from assistive technology
○Custom controls have associated labels
○Custom controls have ARIA roles
●`[aria-hidden="true"]` is not present on the document `<body>`
●Form elements have associated labels
●Document has a `<title>` element
●Links are distinguishable without relying on color.
●Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).
●List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements
●The page contains a heading, skip link, or landmark region
●Identical links have the same purpose.
○`[accesskey]` values are unique
○`[aria-*]` attributes match their roles
○`button`, `link`, and `menuitem` elements have accessible names
○ARIA attributes are used as specified for the element's role
○Deprecated ARIA roles were not used
○Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
○`[aria-hidden="true"]` elements do not contain focusable descendents
○ARIA input fields have accessible names
○ARIA `meter` elements have accessible names
○ARIA `progressbar` elements have accessible names
○Elements use only permitted ARIA attributes
○`[role]`s have all required `[aria-*]` attributes
○Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.
○`[role]`s are contained by their required parent element
○`[role]` values are valid
○Elements with the `role=text` attribute do not have focusable descendents.
○ARIA toggle fields have accessible names
○ARIA `tooltip` elements have accessible names
○ARIA `treeitem` elements have accessible names
○`[aria-*]` attributes have valid values
○`[aria-*]` attributes are valid and not misspelled
○Buttons have an accessible name
○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.
○Definition list items are wrapped in `<dl>` elements
○ARIA IDs are unique
○No form fields have multiple labels
○`<frame>` or `<iframe>` elements have a title
○Heading elements appear in a sequentially-descending order
○`<html>` element has a valid value for its `[lang]` attribute
○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.
○`<input type="image">` elements have `[alt]` text
○The document does not use `<meta http-equiv="refresh">`
○`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
○`<object>` elements have alternate text
○Select elements have associated label elements.
○Skip links are focusable.
○Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.
○`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.
○`[lang]` attributes have a valid value
○`<video>` elements contain a `<track>` element with `[kind="captions"]`
○Tables have different content in the summary attribute and `<caption>`.
○All heading elements contain content.
○Uses ARIA roles only on compatible elements
○Image elements do not have `[alt]` attributes that are redundant text.
○Elements with visible text labels have matching accessible names.
○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.
○`<td>` elements in a large `<table>` have one or more table headers.
69

Best Practices

Trust and Safety

All sites should be protected with HTTPS, even ones that don't handle sensitive data. This includes avoiding mixed content, where some resources are loaded over HTTP despite the initial request being served over HTTPS. HTTPS prevents intruders from tampering with or passively listening in on the communications between your app and your users, and is a prerequisite for HTTP/2 and many new web platform APIs. Learn more about HTTPS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Insecure URLRequest Resolution
www.dangdang.com/Allowed
img63.ddimg.cn/6980a660-38bd-4629-a74e-c79c7c2db431.hpuWMccmAutomatically upgraded to HTTPS
img63.ddimg.cn/upload_img/00459/home/head_sprite.pngAutomatically upgraded to HTTPS
img62.ddimg.cn/upload_img/00459/home/icon_cart.pngAutomatically upgraded to HTTPS
img60.ddimg.cn/upload_img/00111/home/home_sprite_1507.pngAutomatically upgraded to HTTPS
img63.ddimg.cn/upload_img/00446/111/bg_sidebar.pngAutomatically upgraded to HTTPS
img63.ddimg.cn/2019/8/30/2019083014415426253.pngAutomatically upgraded to HTTPS
backend-permanent.ddimg.cn/adsmart/2026/4/14/202604141726085600.jpgAutomatically upgraded to HTTPS

Browser Compatibility

Specifying a doctype prevents the browser from switching to quirks-mode. Learn more about the doctype declaration.

Why this matters

Performance issues directly impact user engagement and conversion rates.

General

Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit

Why this matters

Performance issues directly impact user engagement and conversion rates.

SourceDescription
www.dangdang.com/ line 634, col 156
TypeError: Cannot set properties of null (setting 'innerHTML') at HTMLDocument.<anonymous> (https://www.dangdang.com/:635:157) at r (https://www.dangdang.com/static/script/jquery-1.11.3.min.js:70:22) at Object.fireWith [as resolveWith] (https://www.dangdang.com/static/script/jquery-1.11.3.min.js:71:313) at d.ready (https://www.dangdang.com/static/script/jquery-1.11.3.min.js:75:110) at HTMLDocument.S (https://www.dangdang.com/static/script/jquery-1.11.3.min.js:3:121)

Issues logged to the `Issues` panel in Chrome Devtools indicate unresolved problems. They can come from network request failures, insufficient security controls, and other browser concerns. Open up the Issues panel in Chrome DevTools for more details on each issue.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Issue type
Mixed content
●Avoids deprecated APIs
●Avoids third-party cookies
●Allows users to paste into input fields
●Avoids requesting the geolocation permission on page load
●Avoids requesting the notification permission on page load
●Displays images with correct aspect ratio
●Serves images with appropriate resolution
●Properly defines charset
●Ensure CSP is effective against XSS attacks
●Use a strong HSTS policy
●Ensure proper origin isolation with COOP
●Mitigate clickjacking with XFO or CSP
●Mitigate DOM-based XSS with Trusted Types
●Detected JavaScript libraries
●Page has valid source maps
○Redirects HTTP traffic to HTTPS
69

SEO

These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.

Crawling and Indexing

Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. Learn how to make links crawlable

Why this matters

Performance issues directly impact user engagement and conversion rates.

Uncrawlable Link
div.logo_line > div.search > form#form_search_new > a.del-keywords div.logo_line > div.search > form#form_search_new > a.del-keywords
全部分类 form#form_search_new > span.select > div#search_all_category > a
尾品汇 form#form_search_new > span.select > div#search_all_category > a
图书 form#form_search_new > span.select > div#search_all_category > a
电子书 form#form_search_new > span.select > div#search_all_category > a
音像 form#form_search_new > span.select > div#search_all_category > a
影视 form#form_search_new > span.select > div#search_all_category > a
时尚美妆 form#form_search_new > span.select > div#search_all_category > a
母婴用品 form#form_search_new > span.select > div#search_all_category > a
玩具 form#form_search_new > span.select > div#search_all_category > a
孕婴服饰 form#form_search_new > span.select > div#search_all_category > a
童装童鞋 form#form_search_new > span.select > div#search_all_category > a
家居日用 form#form_search_new > span.select > div#search_all_category > a
家具装饰 form#form_search_new > span.select > div#search_all_category > a
服装 form#form_search_new > span.select > div#search_all_category > a
鞋 form#form_search_new > span.select > div#search_all_category > a
箱包皮具 form#form_search_new > span.select > div#search_all_category > a
手表饰品 form#form_search_new > span.select > div#search_all_category > a
运动户外 form#form_search_new > span.select > div#search_all_category > a
汽车用品 form#form_search_new > span.select > div#search_all_category > a
食品 form#form_search_new > span.select > div#search_all_category > a
手机通讯 form#form_search_new > span.select > div#search_all_category > a
数码影音 form#form_search_new > span.select > div#search_all_category > a
电脑办公 form#form_search_new > span.select > div#search_all_category > a
大家电 form#form_search_new > span.select > div#search_all_category > a
家用电器 form#form_search_new > span.select > div#search_all_category > a
图书 div#navigation > ul.fix_screen_list > li > a.f1
服装 div#navigation > ul.fix_screen_list > li > a.f13
猜你喜欢 div#navigation > ul.fix_screen_list > li > a.f15
div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.collect div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.collect
div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.footprint div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.footprint
div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.cim_entry div#sidebar_wrap_id > div.sidebar > div.sidebar_top > a.cim_entry
div.sidebar > div.sidebar_b > div.sidebar_code2 > a.code2s div.sidebar > div.sidebar_b > div.sidebar_code2 > a.code2s
div#sidebar_wrap_id > div.sidebar > div.sidebar_b > a.back_top div#sidebar_wrap_id > div.sidebar > div.sidebar_b > a.back_top
search div.con > div#33579 > div > a#goStickSearch

If your robots.txt file is malformed, crawlers may not be able to understand how you want your website to be crawled or indexed. Learn more about robots.txt.

Why this matters

Performance issues directly impact user engagement and conversion rates.

To appear in search results, crawlers need access to your app.

Content Best Practices

Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more about the `alt` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
ul.ddnewhead_operate_nav > li.ddnewhead_cart > a > img ul.ddnewhead_operate_nav > li.ddnewhead_cart > a > img
div.logo_line_out > div.logo_line > div.logo > img div.logo_line_out > div.logo_line > div.logo > img
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img
div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img div.footer_pic_new > div.footer_ad_new_inner > a.footer_img > img.footer_ad_img

Canonical links suggest which URL to show in search results. Learn more about canonical links.

Why this matters

Informational: a Permissions-Policy directive showing feature -> allowed origins.

Source: MDN Permissions-Policy

Format your HTML in a way that enables crawlers to better understand your app’s content.

○Structured data is valid
●Page isn’t blocked from indexing
●Document has a `<title>` element
●Document has a meta description
●Page has successful HTTP status code
●Links have descriptive text
●Document has a valid `hreflang`

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