Lighthouse Mobile

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

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Detailed Report

Audit breakdown by category with detailed findings.

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 forced reflow occurs when JavaScript queries geometric properties (such as offsetWidth) after styles have been invalidated by a change to the DOM state. This can result in poor performance. Learn more about forced reflows and possible mitigations.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:source label:Top function call valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:60.149 source:map[column:137998 line:1 type:source-location url:https://c77.bookbot.com/_next/static/chunks/framework-c6c82aad00023883.js urlProvider:network]]]

headings: [map[key:source label:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:112.702 source:map[type:text value:[unattributed]]] map[reflowTime:10.42 source:map[column:50918 line:0 type:source-location url:https://c77.bookbot.com/_next/static/chunks/155-87788944e47d4ea3.js urlProvider:network]] map[reflowTime:46.118 source:map[column:82348 line:0 type:source-location url:https://c77.bookbot.com/_next/static/chunks/5803-44b4c941d125f4db.js urlProvider:network]] map[reflowTime:0.242 source:map[column:7592 line:0 type:source-location url:https://c77.bookbot.com/_next/static/chunks/2761-ff17abfb2a57c664.js urlProvider:network]] map[reflowTime:3.369 source:map[column:93767 line:0 type:source-location url:https://c77.bookbot.com/_next/static/chunks/5803-44b4c941d125f4db.js urlProvider:network]]]

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.

	URL	Resource Size	Est Savings
Mileniálové, pamatujete si své staré knižní lásky? `ul.HomePageBanners_styles_list__k9e2G > li.HomePageBannersItem_styles_root__gjWhB > div.HomePageBannersItem_styles_imageContainer__hpU8Y > img.HomePageBannersItem_styles_image__sAPAv`	/medium_CZ_Knihobot_millennials_HB_banner_1600x1300_view_...	59.1 KiB	54.7 KiB
Pošli knihy do Knihobotu AlzaBoxem! `ul.HomePageBanners_styles_list__k9e2G > li.HomePageBannersItem_styles_root__gjWhB > div.HomePageBannersItem_styles_imageContainer__hpU8Y > img.HomePageBannersItem_styles_image__sAPAv`	/medium_CZ_Knihobot_Alza_HB_banner_1600x1300_view_1_1_710...	46.3 KiB	42.8 KiB
Objev Knihobot Klub plný výhod! `ul.HomePageBanners_styles_list__k9e2G > li.HomePageBannersItem_styles_root__gjWhB > div.HomePageBannersItem_styles_imageContainer__hpU8Y > img.HomePageBannersItem_styles_image__sAPAv`	strapi-c77.bookbot.com/medium_Klub_4_e5785e33bb.jpg	32.5 KiB	30.1 KiB
Sarah J. Maas Půlměsíční město. Rod země a krve `div.ProductCard_styles_picture__kaKq9 > a.ProductCardLink_styles_root__RGJS5 > picture.ProductCardPicture_styles_root__Ce2ir > img`	rezised-images.knhbt.cz/440x440/87461439.webp	18.8 KiB	15.6 KiB
div.ResponsiveContainer_styles_root__iai5v > ul.HomePageBanners_styles_list__k9e2G > li.HomepageBannersSellBooksItem_styles_root__03MzY > img.HomepageBannersSellBooksItem_styles_blob2__Voa_G `div.ResponsiveContainer_styles_root__iai5v > ul.HomePageBanners_styles_list__k9e2G > li.HomepageBannersSellBooksItem_styles_root__03MzY > img.HomepageBannersSellBooksItem_styles_blob2__Voa_G`	c77.bookbot.com/_next/static/media/blob-2.4eac3eed.png	17.9 KiB	15.5 KiB
Sarah J. Maas Půlnoční koruna `div.ProductCard_styles_picture__kaKq9 > a.ProductCardLink_styles_root__RGJS5 > picture.ProductCardPicture_styles_root__Ce2ir > img`	rezised-images.knhbt.cz/440x440/91304024.webp	16.3 KiB	13.6 KiB
Sarah J. Maas Království popela `div.ProductCard_styles_picture__kaKq9 > a.ProductCardLink_styles_root__RGJS5 > picture.ProductCardPicture_styles_root__Ce2ir > img`	rezised-images.knhbt.cz/440x440/91304417.webp	16.1 KiB	13.4 KiB
div.ResponsiveContainer_styles_root__iai5v > ul.HomePageBanners_styles_list__k9e2G > li.HomepageBannersSellBooksItem_styles_root__03MzY > img.HomepageBannersSellBooksItem_styles_blob1__yfFiu `div.ResponsiveContainer_styles_root__iai5v > ul.HomePageBanners_styles_list__k9e2G > li.HomepageBannersSellBooksItem_styles_root__03MzY > img.HomepageBannersSellBooksItem_styles_blob1__yfFiu`	c77.bookbot.com/_next/static/media/blob-1.8e4a8eaf.png	13.1 KiB	11.6 KiB

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:445.514998046875 label:Time to first byte subpart:timeToFirstByte] map[duration:2189.770001953125 label:Element render delay subpart:elementRenderDelay]]

lhId: page-8-P

nodeLabel: Na našem webu pracujeme s cookies a osobními údaji. Moc by nám pomohlo, kdybych…

path: 1,HTML,1,BODY,5,DIV,0,DIV,0,DIV,1,DIV,0,DIV,1,P

selector: div.cm > div.cm__body > div.cm__texts > p#cm__desc

snippet: <p id="cm__desc" class="cm__desc">

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.

More than 4 preconnect connections were found. These should be used sparingly and only to the most important origins.

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

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

value: No additional origins are good candidates for preconnecting

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.

Request	Cache TTL	Transfer Size
l.seznam.cz/static/js/sem.js?szn_loader=1	3600.0 s	68.8 KiB
cms.knihobot.cz/wp-content/uploads/2026/02/CZ_watch-dog-banner-web.webp	600.0 s	41.3 KiB

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

The maximum potential First Input Delay that your users could experience is the duration of the longest task. Learn more about the Maximum Potential First Input Delay metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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 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: 300 ms 38.1 KiB

URL	Transfer Size	Est Savings
c77.bookbot.com/_next/static/css/bb22fe22a5be5034.css	39.9 KiB	38.1 KiB

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: 760 ms 902.7 KiB

URL	Transfer Size	Est Savings
c77.bookbot.com/_next/static/chunks/5581-5141ebacfaf076b5.js	188.3 KiB	137.8 KiB
www.googletagmanager.com/gtag/destination?id=AW-894320112&cx=c&gtm=4e6921	158.4 KiB	74.6 KiB
www.googletagmanager.com/gtag/js?id=G-N116K2C2SM&cx=c&gtm=4e6921	182.0 KiB	71.7 KiB
www.googletagmanager.com/gtag/js?id=G-000&cx=c&gtm=4e6921	146.8 KiB	68.5 KiB
www.googletagmanager.com/gtm.js?id=GTM-TF5RV29	196.1 KiB	65.5 KiB
c77.bookbot.com/_next/static/chunks/4586-e8ea1f603aeb7f0a.js	111.6 KiB	62.5 KiB
c77.bookbot.com/_next/static/chunks/pages/_app-3f66b878bb9e3ed3.js	143.9 KiB	62.2 KiB
c77.bookbot.com/_next/static/chunks/pages/sell-books-b3e6559af12f4c3c.js	77.6 KiB	57.0 KiB
c77.bookbot.com/_next/static/chunks/f69bbb46-db551f39eee35ab4.js	67.9 KiB	49.9 KiB
c77.bookbot.com/_next/static/chunks/2606-73fb6db06fc090ae.js	69.4 KiB	47.5 KiB
l.seznam.cz/sul.js?id=hga0pgy1bxumavnfoh0d5arq	103.0 KiB	43.0 KiB
c77.bookbot.com/_next/static/chunks/pages/cart-c9bc3cbadca9fd53.js	63.6 KiB	42.3 KiB
l.seznam.cz/static/js/sem.js?szn_loader=1	68.5 KiB	38.8 KiB
c77.bookbot.com/_next/static/chunks/22f692b0-ffc205d9e6e401f3.js	34.5 KiB	31.3 KiB
c77.bookbot.com/_next/static/chunks/5843-0d3d3a3335984bc9.js	34.9 KiB	26.9 KiB
c77.bookbot.com/_next/static/chunks/5803-44b4c941d125f4db.js	39.9 KiB	23.2 KiB

Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Total CPU Time	Script Evaluation	Script Parse
c77.bookbot.com/_next/static/chunks/framework-c6c82aad00023883.js	5.7 s	3.5 s	22 ms
knihobot.cz/	2.8 s	11 ms	2.1 ms
c77.bookbot.com/_next/static/chunks/pages/_app-3f66b878bb9e3ed3.js	1.0 s	264 ms	74 ms
www.googletagmanager.com/gtm.js?id=GTM-TF5RV29	840 ms	717 ms	105 ms
Unattributable	832 ms	38 ms	0.0 ms
www.googletagmanager.com/gtag/js?id=G-N116K2C2SM&cx=c&gtm=4e6921	517 ms	407 ms	82 ms
www.googletagmanager.com/gtag/destination?id=AW-894320112&cx=c&gtm=4e6921	485 ms	406 ms	75 ms
www.googletagmanager.com/gtag/js?id=G-000&cx=c&gtm=4e6921	314 ms	249 ms	63 ms
c77.bookbot.com/_next/static/chunks/pages/index-c9875874d13834ca.js	303 ms	295 ms	3.4 ms
c77.bookbot.com/_next/static/chunks/main-9b896f863166457a.js	221 ms	190 ms	19 ms
c77.bookbot.com/_next/static/chunks/5803-44b4c941d125f4db.js	154 ms	13 ms	22 ms
c77.bookbot.com/_next/static/chunks/5581-5141ebacfaf076b5.js	153 ms	124 ms	29 ms
l.seznam.cz/static/js/sem.js?szn_loader=1	149 ms	112 ms	34 ms
c77.bookbot.com/_next/static/chunks/5870-9e097eff542a4ada.js	144 ms	23 ms	17 ms
c77.bookbot.com/_next/static/chunks/pages/sell-books-b3e6559af12f4c3c.js	144 ms	132 ms	12 ms
l.seznam.cz/sul.js?id=hga0pgy1bxumavnfoh0d5arq	119 ms	103 ms	15 ms
c77.bookbot.com/_next/static/chunks/6157.6050915882fa2f3e.js	77 ms	69 ms	7.3 ms
c77.bookbot.com/i18n/cs.1b36f6eada48.js	63 ms	16 ms	47 ms
c77.bookbot.com/_next/static/chunks/pages/cart-c9bc3cbadca9fd53.js	54 ms	44 ms	9.5 ms

Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to minimize main-thread work

Why this matters

Performance issues directly impact user engagement and conversion rates.

Category	Time Spent
Script Evaluation	6.8 s
Other	4.1 s
Style & Layout	2.2 s
Script Parsing & Compilation	853 ms
Rendering	298 ms
Garbage Collection	198 ms
Parse HTML & CSS	136 ms

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 reason	Failure type
Pages with cache-control:no-store header cannot enter back/forward cache.	Actionable
Pages whose main resource has cache-control:no-store cannot enter back/forward cache.	Not actionable
Back/forward cache is disabled because some JavaScript network request received resource with Cache-Control: no-store header.	Not actionable

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

●Layout shift culprits

●Document request latency

●Optimize DOM size

●Font display

●Modern HTTP

●Render blocking requests

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Avoids enormous network payloads Total size was 2,359 KiB

●User Timing marks and measures 4 user timings

●Avoid long main-thread tasks 20 long tasks found

●Avoid non-composited animations 2 animated elements found

●Image elements have explicit `width` and `height`

●Network Requests

●Network Round Trip Times 100 ms

●Server Backend Latencies 100 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Avoid multiple page redirects

●Initial server response time was short Root document took 270 ms

○INP breakdown

○LCP request discovery

○Avoid large layout shifts

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
div.HeaderSearch_styles_root__P3kpS > form.HeaderSearchForm_styles_root__vb_ss > div.HeaderSearchFormInput_styles_root__r7sFw > input#:Rd5bj6: `div.HeaderSearch_styles_root__P3kpS > form.HeaderSearchForm_styles_root__vb_ss > div.HeaderSearchFormInput_styles_root__r7sFw > input#:Rd5bj6:`
Sarah J. Maas `div.ProductCardCarouselItem_styles_root__9mII6 > article.ProductCard_styles_root__qkYLe > div.ProductCard_styles_body__w8HDH > a.ProductCardBodyAuthors_styles_root__BRhTT`
Skladem 6 ks `article.ProductCard_styles_root__qkYLe > div.ProductCard_styles_body__w8HDH > div.ProductCardBody_styles_stateAndFlags__dWCP4 > div.ProductCardBodyState_styles_root__bS8_k`
Sarah J. Maas `div.ProductCardCarouselItem_styles_root__9mII6 > article.ProductCard_styles_root__qkYLe > div.ProductCard_styles_body__w8HDH > a.ProductCardBodyAuthors_styles_root__BRhTT`
Skladem 9 ks `article.ProductCard_styles_root__qkYLe > div.ProductCard_styles_body__w8HDH > div.ProductCardBody_styles_stateAndFlags__dWCP4 > div.ProductCardBodyState_styles_root__bS8_k`
Žádná kniha už ti neunikne `div.CMSPromo_styles_root__t11DG > div.CMSPromo_styles_contentWrapper__yF7Wi > div.CMSPromo_styles_wrapper__FYgej > h3.CMSPromo_styles_label__TOxUs`
Za posledních 24 h jsme přidali 36 354 knih. To je na výšku jako 11,4 Petřínský… `div.FooterHead_styles_root__okxbN > div > div.FooterHead_styles_addedBooksWrapper__klXa_ > p.Typography_styles_typography__xNmkQ`
36 354 `div > div.FooterHead_styles_addedBooksWrapper__klXa_ > p.Typography_styles_typography__xNmkQ > span.Typography_styles_typography__xNmkQ`
11,4 `div > div.FooterHead_styles_addedBooksWrapper__klXa_ > p.Typography_styles_typography__xNmkQ > span.Typography_styles_typography__xNmkQ`
Bezpečnou platbu zajistí `div.ResponsiveContainer_styles_root__iai5v > div.FooterServices_styles_root__dc0Gx > div.FooterServicesPayment_styles_root__bC98k > p.Typography_styles_typography__xNmkQ`
O rychlé dodání se postará `div.ResponsiveContainer_styles_root__iai5v > div.FooterServices_styles_root__dc0Gx > div.FooterServicesCarriers_styles_root__8HbVw > p.Typography_styles_typography__xNmkQ`
Obchodní podmínky pro nákup `nav > ul.FooterServicesLinksLegal_styles_list__F2tTw > li > a.FooterServicesLinksLegal_styles_link__V73xz`
Obchodní podmínky pro obstarání prodeje `nav > ul.FooterServicesLinksLegal_styles_list__F2tTw > li > a.FooterServicesLinksLegal_styles_link__V73xz`
Ochrana osobních údajů `nav > ul.FooterServicesLinksLegal_styles_list__F2tTw > li > a.FooterServicesLinksLegal_styles_link__V73xz`
Knihy bez cenzury `nav > ul.FooterServicesLinksLegal_styles_list__F2tTw > li > a.FooterServicesLinksLegal_styles_link__V73xz`
SK `nav.FooterServicesLinksSite_styles_root__rDYDH > ul.FooterServicesLinksSite_styles_list__1xDSH > li > a.FooterServicesLinksSite_styles_link__hoVTk`
AT `nav.FooterServicesLinksSite_styles_root__rDYDH > ul.FooterServicesLinksSite_styles_list__1xDSH > li > a.FooterServicesLinksSite_styles_link__hoVTk`
DE `nav.FooterServicesLinksSite_styles_root__rDYDH > ul.FooterServicesLinksSite_styles_list__1xDSH > li > a.FooterServicesLinksSite_styles_link__hoVTk`
COM `nav.FooterServicesLinksSite_styles_root__rDYDH > ul.FooterServicesLinksSite_styles_list__1xDSH > li > a.FooterServicesLinksSite_styles_link__hoVTk`
ES `nav.FooterServicesLinksSite_styles_root__rDYDH > ul.FooterServicesLinksSite_styles_list__1xDSH > li > a.FooterServicesLinksSite_styles_link__hoVTk`
IT `nav.FooterServicesLinksSite_styles_root__rDYDH > ul.FooterServicesLinksSite_styles_list__1xDSH > li > a.FooterServicesLinksSite_styles_link__hoVTk`
NL `nav.FooterServicesLinksSite_styles_root__rDYDH > ul.FooterServicesLinksSite_styles_list__1xDSH > li > a.FooterServicesLinksSite_styles_link__hoVTk`
FR `nav.FooterServicesLinksSite_styles_root__rDYDH > ul.FooterServicesLinksSite_styles_list__1xDSH > li > a.FooterServicesLinksSite_styles_link__hoVTk`
BE `nav.FooterServicesLinksSite_styles_root__rDYDH > ul.FooterServicesLinksSite_styles_list__1xDSH > li > a.FooterServicesLinksSite_styles_link__hoVTk`
PL `nav.FooterServicesLinksSite_styles_root__rDYDH > ul.FooterServicesLinksSite_styles_list__1xDSH > li > a.FooterServicesLinksSite_styles_link__hoVTk`

These are opportunities to improve the legibility of your content.

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
Pouze 449 Kč `div.ProductCardBody_styles_priceRowWithDeal__ZAFjZ > div.ProductCardBodyDeal_styles_root__7n2UI > p.Typography_styles_typography__xNmkQ > a.ProductCardLink_styles_root__RGJS5`
Pro členy Klubu `div.ProductCardBody_styles_priceRowWithDeal__ZAFjZ > div.ProductCardBodyDeal_styles_root__7n2UI > p.Typography_styles_typography__xNmkQ > a`
Pouze 323 Kč `div.ProductCardBody_styles_priceRowWithDeal__ZAFjZ > div.ProductCardBodyDeal_styles_root__7n2UI > p.Typography_styles_typography__xNmkQ > a.ProductCardLink_styles_root__RGJS5`
Pro členy Klubu `div.ProductCardBody_styles_priceRowWithDeal__ZAFjZ > div.ProductCardBodyDeal_styles_root__7n2UI > p.Typography_styles_typography__xNmkQ > a`

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-*]` attributes match their roles

●`[aria-hidden="true"]` is not present on the document `<body>`

●`[role]`s have all required `[aria-*]` attributes

●`[role]` values are valid

●`[aria-*]` attributes have valid values

●`[aria-*]` attributes are valid and not misspelled

●Buttons have an accessible name

●Image elements have `[alt]` attributes

●Form elements have associated labels

●`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.

●ARIA attributes are used as specified for the element's role

●Elements with `role="dialog"` or `role="alertdialog"` have accessible names.

●`[aria-hidden="true"]` elements do not contain focusable descendents

●Elements use only permitted ARIA attributes

●Document has a `<title>` element

●`<html>` element has a `[lang]` attribute

●`<html>` element has a valid value for its `[lang]` attribute

●Links are distinguishable without relying on color.

●Links have a discernible name

●Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).

●List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements

●No element has a `[tabindex]` value greater than 0

●Heading elements appear in a sequentially-descending order

●Document has a main landmark.

●Deprecated ARIA roles were not used

●Identical links have the same purpose.

○`[accesskey]` values are unique

○`button`, `link`, and `menuitem` elements have accessible names

○ARIA input fields have accessible names

○ARIA `meter` elements have accessible names

○ARIA `progressbar` elements have accessible names

○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

○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

○The page contains a heading, skip link, or landmark region

○`<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

○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.

○Input buttons have discernible text.

○`<input type="image">` elements have `[alt]` text

○The document does not use `<meta http-equiv="refresh">`

○`<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.

Best Practices

User Experience

Image natural dimensions should be proportional to the display size and the pixel ratio to maximize image clarity. Learn how to provide responsive images.

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL	Displayed size	Actual size	Expected size
div.ResponsiveContainer_styles_root__iai5v > ul.HomePageBanners_styles_list__k9e2G > li.HomepageBannersSellBooksItem_styles_root__03MzY > img.HomepageBannersSellBooksItem_styles_blob2__Voa_G `div.ResponsiveContainer_styles_root__iai5v > ul.HomePageBanners_styles_list__k9e2G > li.HomepageBannersSellBooksItem_styles_root__03MzY > img.HomepageBannersSellBooksItem_styles_blob2__Voa_G`	c77.bookbot.com/_next/static/media/blob-2.4eac3eed.png	107 x 141	107 x 141	161 x 212
div.ResponsiveContainer_styles_root__iai5v > ul.HomePageBanners_styles_list__k9e2G > li.HomepageBannersSellBooksItem_styles_root__03MzY > img.HomepageBannersSellBooksItem_styles_blob1__yfFiu `div.ResponsiveContainer_styles_root__iai5v > ul.HomePageBanners_styles_list__k9e2G > li.HomepageBannersSellBooksItem_styles_root__03MzY > img.HomepageBannersSellBooksItem_styles_blob1__yfFiu`	c77.bookbot.com/_next/static/media/blob-1.8e4a8eaf.png	122 x 74	122 x 74	183 x 111

●Uses HTTPS

●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

●Page has the HTML doctype

●Properly defines charset

●No browser errors logged to the console

●No issues in the `Issues` panel in Chrome Devtools

●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

100

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.

○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

●Links are crawlable

●robots.txt is valid

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`