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Lighthouse Mobile

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

Audit breakdown by category with detailed findings.

25

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
s.ntv.io/serve/load.js3600.0 s251.1 KiB
/33e288f1-17a3-4a1f-b7ab-6d5d5187c6d0-web.js900.0 s145.2 KiB
/scripts/2f59fd7b262f6397e696a1e932324a401ff859c8dd36797a...3600.0 s120.5 KiB
cdn-eu.piano.io/api/tinypass.min.js14400.0 s132.8 KiB
connect.facebook.net/en_US/fbevents.js1200.0 s96.6 KiB
client.aps.amazon-adsystem.com/publisher.js3600.0 s82.2 KiB
/pagead/managed/js/activeview/current/ufs_web_display.js3600.0 s73.1 KiB
ak.sail-horizon.com/spm/spm.v1.min.js600.0 s48.1 KiB
/signals/config/353120065084216?v=2.9.303&r=stable&domain...1200.0 s46.5 KiB
cdn.cxense.com/cx.js3600.0 s38.1 KiB
cmp.dmgmediaprivacy.co.uk/ccpa/2.8.18-ccpa-46/iife/mol-ads-cmp.js68810.0 s48.5 KiB
secure.cdn.fastclick.net/js/pubcid/latest/pubcid.min.js900.0 s21.7 KiB
www.redditstatic.com/ads/pixel.js60.0 s19.0 KiB
cmp.dmgmediaprivacy.co.uk/ccpa/2.8.18-ccpa-46/iife/polyfill.min.js67480.0 s41.9 KiB
cmp.dmgmediaprivacy.co.uk/ccpa/2.8.18-ccpa-46/iife/mol-ads-cmp.min.js16237.0 s27.6 KiB
scripts.clarity.ms/0.8.59/clarity.js86400.0 s26.2 KiB
rta2.newscientist.com/s/rta3/rta-newscientist-3.min.js59.0 s8.9 KiB
cmp.dmgmediaprivacy.co.uk/ccpa/2.8.18-ccpa-46/css/mobile.css68979.0 s17.9 KiB
static.chartbeat.com/js/chartbeat.js86400.0 s16.1 KiB
tag.rmp.rakuten.com/123951.ct.js86400.0 s15.5 KiB
/ng/common/i18n/platform-translation-map_en_US.js?version...86400.0 s14.0 KiB
cdn.cxense.com/cx.cce.js3600.0 s6.8 KiB
eus.rubiconproject.com/usync.js59155.0 s11.5 KiB
/_sam/H4sIAAAAAAAA_z3IwQ6AIAgA0B9KmJ76m4bJHI6oBa7f7-bt7eE...603716.0 s52.6 KiB
/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da177152312...86400.0 s10.7 KiB
static.chartbeat.com/js/chartbeat_mab.js86400.0 s10.1 KiB
/showtemplate/general/loadTranslationMap?aid=rba4f1Zcpe&v...86400.0 s9.8 KiB
buy-eu.piano.io/widget/dist/template/css/template.bundle.1.0.css14400.0 s5.5 KiB
experience-eu.piano.io/xbuilder/experience/load?aid=rba4f1Zcpe1800.0 s2.4 KiB
www.npttech.com/advertising.js28800.0 s3.1 KiB
cdn-ima.33across.com/ima.js259200.0 s6.9 KiB
config.aps.amazon-adsystem.com/configs/30653600.0 s1.7 KiB
tpc.googlesyndication.com/pagead/js/r20260420/r20110914/abg_lite_fy2021.js1209600.0 s8.4 KiB
applets.ebxcdn.com/ebx.js7200.0 s1.0 KiB
/rp.gif?ts=1776799051633&id=a2_gntgt9dbr3jj&event=PageVis...0.0 ms666 B
/cookie?redirect_url=https%3A%2F%2Felb.the-ozone-project....0.0 ms475 B
/track/cmb/generic?ttd_pid=u40cpuw&ttd_tpi=1&gdpr=0&gdpr_...0.0 ms253 B
/ul_cb/dsp_match/275?ssp=524&gdpr=%7Bgdpr%7D&gdpr_consent...0.0 ms198 B
/ul_cb/server_match?gdpr=0&gdpr_consent=&us_privacy=1YNN&...0.0 ms198 B
/pagead/js/r20260420/r20110914/client/window_focus_fy2021.js1209600.0 s1.6 KiB
/cm-notify?pi=uk-ozone-pbs&gdpr=0&gdpr_consent=&us_privac...0.0 ms124 B
cdn.indexww.com/ht/htw-pixel.gif?086400.0 s246 B
/p.css?s=1&k=zvd4ukw&ht=tk&f=5088.5404.4528.4549.5028.519...604800.0 s173 B
/tr/?id=353120065084216&ev=PageView&dl=https%3A%2F%2Fwww....0.0 ms16 B
/tr/?id=353120065084216&ev=PermutiveSegmentEntry&dl=https...0.0 ms16 B
/tr/?id=353120065084216&ev=PermutiveSegmentEntry_104483&d...0.0 ms16 B
/tr/?id=353120065084216&ev=PermutiveSegmentEntry&dl=https...0.0 ms16 B
/tr/?id=353120065084216&ev=PermutiveSegmentEntry_11018&dl...0.0 ms16 B
/tr/?id=353120065084216&ev=PermutiveSegmentEntry&dl=https...0.0 ms16 B
/tr/?id=353120065084216&ev=PermutiveSegmentEntry_41056&dl...0.0 ms16 B
/tr/?id=353120065084216&ev=PermutiveSegmentEntry&dl=https...0.0 ms16 B
/tr/?id=353120065084216&ev=PermutiveSegmentEntry_76151&dl...0.0 ms16 B
/tr/?id=353120065084216&ev=PermutiveSegmentEntry&dl=https...0.0 ms16 B
/tr/?id=353120065084216&ev=PermutiveSegmentEntry_9897&dl=...0.0 ms16 B
/pagead/managed/js/activeview/current/ufs_web_display.js3600.0 s0 B
/pagead/managed/js/activeview/current/ufs_web_display.js3600.0 s0 B
/_sam/H4sIAAAAAAAA_z3IwQ6AIAgA0B9KmJ76m4bJHI6oBa7f7-bt7eE...603716.0 s0 B
/ng/common/i18n/platform-translation-map_en_US.js?version...86400.0 s0 B
/showtemplate/general/loadTranslationMap?aid=rba4f1Zcpe&v...86400.0 s0 B
buy-eu.piano.io/widget/dist/template/css/template.bundle.1.0.css14400.0 s0 B
tpc.googlesyndication.com/pagead/js/r20260420/r20110914/abg_lite_fy2021.js1209600.0 s0 B
tpc.googlesyndication.com/pagead/js/r20260420/r20110914/abg_lite_fy2021.js1209600.0 s0 B
/pagead/js/r20260420/r20110914/client/window_focus_fy2021.js1209600.0 s0 B
/pagead/js/r20260420/r20110914/client/window_focus_fy2021.js1209600.0 s0 B

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.

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:1.635 source:map[column:39879 line:2 type:source-location url:https://www.newscientist.com/build/6603.174325d7.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:75.676 source:map[column:5404 line:0 type:source-location url:https://www.newscientist.com/build/base/homepage.7bc8d59f.js urlProvider:network]] map[reflowTime:1.635 source:map[column:39189 line:1 type:source-location url:https://www.newscientist.com/build/6603.174325d7.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.

URLResource SizeEst Savings
How we discovered the speed limit of arithmetic – and broke it div.Card__ImageWrapper > div.Card__ImageOverflow > div.Image__Wrapper > img.Image
/wp-content/uploads/2026/04/13175115/SEI_293041785.jpg?wi...48.9 KiB33.7 KiB
Nanodiamonds div.Card__ImageWrapper > div.Card__ImageOverflow > div.Image__Wrapper > img.Image
/wp-content/uploads/2026/04/20201833/SEI_293915450.jpg?wi...38.1 KiB27.5 KiB
A vessel heading towards the Strait of Hormuz div.Card__ImageWrapper > div.Card__ImageOverflow > div.Image__Wrapper > img.Image
/wp-content/uploads/2026/04/21133208/SEI_293951796.jpg?wi...33.9 KiB24.4 KiB
Can you determine your personalised stress score? div.Card__ImageWrapper > div.Card__ImageOverflow > div.Image__Wrapper > img.Image
/wp-content/uploads/2026/04/16155919/SEI_293150549.jpg?wi...26.7 KiB19.2 KiB
Can we ‘vaccinate’ ourselves against stress? div.Card__ImageWrapper > div.Card__ImageOverflow > div.Image__Wrapper > img.Image
/wp-content/uploads/2026/04/16155914/SEI_293150298.jpg?wi...24.7 KiB17.8 KiB
New Scientist. Science news and long reads from expert journalists, covering de… div.MarketingPanel__ContentWrapper > div.MarketingPanel__ImageWrapper > div.Image__Wrapper > img.Image
/wp-content/uploads/2026/04/15110004/nsl-launch-panel-mob...23.5 KiB17.3 KiB
body.jar > div#google_image_div > a#aw0 > img.img_ad body.jar > div#google_image_div > a#aw0 > img.img_ad
tpc.googlesyndication.com/simgad/678120702608740136217.9 KiB15.3 KiB
div.Card__ImageWrapper > div.Card__ImageOverflow > div.Image__Wrapper > img.Image div.Card__ImageWrapper > div.Card__ImageOverflow > div.Image__Wrapper > img.Image
/wp-content/uploads/2026/04/20135200/SEI_293924114.jpg?wi...19.3 KiB13.9 KiB
New Scientist. Science news and long reads from expert journalists, covering de… div.MarketingPanel__CopyWrapper > div.MarketingPanel__LogoWrapper > div.Image__Wrapper > img.Image
/wp-content/uploads/2026/04/16122755/ns-live-stacked-ligh...14.1 KiB9.0 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:342.6220002441406 label:Time to first byte subpart:timeToFirstByte] map[duration:21.602999755859376 label:Resource load delay subpart:resourceLoadDelay] map[duration:31.014 label:Resource load duration subpart:resourceLoadDuration] map[duration:2677.766 label:Element render delay subpart:elementRenderDelay]]
lhId: page-0-IMG
nodeLabel: How we discovered the speed limit of arithmetic – and broke it
path: 1,HTML,1,BODY,6,MAIN,0,DIV,0,DIV,0,DIV,0,A,0,ARTICLE,0,DIV,0,DIV,0,DIV,0,IMG
selector: div.Card__ImageWrapper > div.Card__ImageOverflow > div.Image__Wrapper > img.Image
snippet: <img class="Image ImageLoaded" alt="How we discovered the speed limit of arithmetic – and broke it" width="1350" height="900" src="https://images.newscientist.com/wp-content/uploads/2026/04/13175115/SEI_29…" srcset="https://images.newscientist.com/wp-content/uploads/2026/04/13175115/SEI_29…" sizes="(min-width: 1360px) 564px, (min-width: 1024px) calc(34.41vw + 89px), (min-…" loading="eager" fetchpriority="high" data-image-context="Card--Hero" data-caption="" data-credit="Renaud Vigourt" pinger-seen="true">

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
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

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 SizeDuration
dmg-libs.anm.co.uk/a/1.88.0/config.js80.0 KiB2.3 s

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

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

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.

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: 989 ms
URLTime Spent
newscientist.com/989 ms
www.newscientist.com/0.0 ms

Diagnostics

Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 150 ms 16.4 KiB
URLTransfer SizeEst Savings
cmp.dmgmediaprivacy.co.uk/ccpa/2.8.18-ccpa-46/iife/mol-ads-cmp.js48.3 KiB16.4 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: 4.7 s 1.0 MiB
URLTransfer SizeEst Savings
s.ntv.io/serve/load.js250.4 KiB190.2 KiB
dmg-libs.anm.co.uk/a/1.88.0/222.js207.2 KiB100.6 KiB
/pagead/managed/js/gpt/m202604170101/pubads_impl.js?cb=31...187.4 KiB88.5 KiB
cdn-eu.piano.io/api/tinypass.min.js132.1 KiB70.0 KiB
www.googletagmanager.com/gtag/js?id=G-N0NXS34EMT&cx=c&gtm=4e64h1171.1 KiB65.7 KiB
www.googletagmanager.com/gtag/js?id=AW-1060321608&cx=c&gtm=4e64h1144.2 KiB61.8 KiB
www.googletagmanager.com/gtag/js?id=DC-5181616&cx=c&gtm=4e64h1130.0 KiB60.4 KiB
www.googletagmanager.com/gtag/js?id=AW-10897141567&cx=c&gtm=4e64h1137.8 KiB53.5 KiB
www.googletagmanager.com/gtm.js?id=GTM-TH2S733K185.3 KiB51.3 KiB
www.newscientist.com/build/2638.e66c3ee5.js54.4 KiB45.7 KiB
dmg-libs.anm.co.uk/a/1.88.0/config.js79.8 KiB43.3 KiB
client.aps.amazon-adsystem.com/publisher.js81.8 KiB33.3 KiB
ak.sail-horizon.com/spm/spm.v1.min.js47.7 KiB32.5 KiB
connect.facebook.net/en_US/fbevents.js96.5 KiB31.4 KiB
/pagead/managed/js/activeview/current/ufs_web_display.js73.1 KiB31.0 KiB
/pagead/managed/js/activeview/current/ufs_web_display.js73.1 KiB31.0 KiB
/pagead/managed/js/activeview/current/ufs_web_display.js73.1 KiB30.3 KiB
cdn.cxense.com/cx.js37.5 KiB24.2 KiB
cmp.dmgmediaprivacy.co.uk/ccpa/2.8.18-ccpa-46/iife/mol-ads-cmp.js48.3 KiB21.2 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.

URLTotal CPU TimeScript EvaluationScript Parse
/scripts/2f59fd7b262f6397e696a1e932324a401ff859c8dd36797a...2.0 s1.7 s203 ms
Unattributable1.9 s532 ms0.0 ms
/33e288f1-17a3-4a1f-b7ab-6d5d5187c6d0-web.js1.4 s1.1 s80 ms
/pagead/managed/js/gpt/m202604170101/pubads_impl.js?cb=31...1.4 s1.3 s73 ms
www.googletagmanager.com/gtm.js?id=GTM-TH2S733K1.3 s1.1 s93 ms
www.newscientist.com/build/2638.e66c3ee5.js1.0 s987 ms23 ms
cdn-eu.piano.io/api/tinypass.min.js740 ms420 ms57 ms
dmg-libs.anm.co.uk/a/1.88.0/config.js604 ms548 ms33 ms
www.newscientist.com/543 ms80 ms18 ms
dmg-libs.anm.co.uk/a/1.88.0/222.js487 ms402 ms77 ms
s.ntv.io/serve/load.js481 ms337 ms126 ms
www.googletagmanager.com/gtag/js?id=G-N0NXS34EMT&cx=c&gtm=4e64h1400 ms325 ms65 ms
/pagead/managed/js/activeview/current/ufs_web_display.js387 ms323 ms30 ms
www.newscientist.com/build/base/homepage.7bc8d59f.js325 ms13 ms1.3 ms
scripts.clarity.ms/0.8.59/clarity.js318 ms224 ms19 ms
client.aps.amazon-adsystem.com/publisher.js305 ms248 ms42 ms
cmp.dmgmediaprivacy.co.uk/ccpa/2.8.18-ccpa-46/iife/mol-ads-cmp.js305 ms261 ms38 ms
cdn.cxense.com/cx.js214 ms150 ms15 ms
www.newscientist.com/build/6603.174325d7.js190 ms126 ms6.9 ms
www.googletagmanager.com/gtag/js?id=AW-1060321608&cx=c&gtm=4e64h1186 ms139 ms46 ms
www.googletagmanager.com/gtag/js?id=AW-10897141567&cx=c&gtm=4e64h1182 ms134 ms46 ms
/signals/config/353120065084216?v=2.9.303&r=stable&domain...179 ms150 ms26 ms
www.googletagmanager.com/gtag/js?id=DC-5181616&cx=c&gtm=4e64h1170 ms126 ms43 ms
connect.facebook.net/en_US/fbevents.js165 ms123 ms41 ms
fundingchoicesmessages.google.com/i/5765?ers=3133 ms128 ms2.9 ms
sdk.apptentive.com/v1/sdk.min.js131 ms108 ms15 ms
tag.rmp.rakuten.com/123951.ct.js119 ms104 ms6.2 ms
static.chartbeat.com/js/chartbeat.js98 ms89 ms5.2 ms
rta2.newscientist.com/s/rta3/rta-newscientist-3.min.js98 ms82 ms3.5 ms
ep2.adtrafficquality.google/sodar/sodar2.js96 ms89 ms2.8 ms
ak.sail-horizon.com/spm/spm.v1.min.js96 ms77 ms17 ms
securepubads.g.doubleclick.net/tag/js/gpt.js?network-code=576593 ms79 ms13 ms
config.aps.amazon-adsystem.com/configs/306580 ms74 ms3.8 ms
secure.cdn.fastclick.net/js/pubcid/latest/pubcid.min.js76 ms65 ms9.9 ms
/t?ntv_mvi=&us_privacy=1YNN&ntv_oos=0&ntv_url=https%253A%...70 ms65 ms1.2 ms
static.chartbeat.com/js/chartbeat_mab.js70 ms56 ms6.6 ms
cdn-ima.33across.com/ima.js62 ms51 ms3.1 ms
www.redditstatic.com/ads/pixel.js62 ms30 ms8.6 ms
tpc.googlesyndication.com/pagead/js/r20260420/r20110914/abg_lite_fy2021.js55 ms36 ms13 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.

CategoryTime Spent
Script Evaluation12.4 s
Other2.1 s
Script Parsing & Compilation1.3 s
Style & Layout625 ms
Parse HTML & CSS241 ms
Garbage Collection217 ms
Rendering173 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 reasonFailure type
The page has an unload handler in the main frame.Actionable
The page has an unload handler in a sub frame.Actionable

Minifying CSS files can reduce network payload sizes. Learn how to minify CSS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 12.8 KiB
URLTransfer SizeEst Savings
cmp.dmgmediaprivacy.co.uk/ccpa/2.8.18-ccpa-46/css/mobile.css17.9 KiB12.8 KiB

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 64.3 KiB
URLTransfer SizeEst Savings
*,:after,:before{box-sizing:border-box} …54.6 KiB48.2 KiB
cmp.dmgmediaprivacy.co.uk/ccpa/2.8.18-ccpa-46/css/mobile.css17.7 KiB16.1 KiB

Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLTransfer Size
s.ntv.io/serve/load.js251.1 KiB
dmg-libs.anm.co.uk/a/1.88.0/222.js207.4 KiB
/pagead/managed/js/gpt/m202604170101/pubads_impl.js?cb=31...187.4 KiB
www.googletagmanager.com/gtm.js?id=GTM-TH2S733K185.7 KiB
www.googletagmanager.com/gtag/js?id=G-N0NXS34EMT&cx=c&gtm=4e64h1171.2 KiB
/33e288f1-17a3-4a1f-b7ab-6d5d5187c6d0-web.js145.2 KiB
www.googletagmanager.com/gtag/js?id=AW-1060321608&cx=c&gtm=4e64h1144.3 KiB
www.googletagmanager.com/gtag/js?id=AW-10897141567&cx=c&gtm=4e64h1137.9 KiB
cdn-eu.piano.io/api/tinypass.min.js132.8 KiB
www.googletagmanager.com/gtag/js?id=DC-5181616&cx=c&gtm=4e64h1130.1 KiB

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

●Layout shift culprits
●Optimize DOM size
●Font display
●LCP request discovery
●Modern HTTP
●Optimize viewport for mobile
●User Timing marks and measures 20 user timings
●Avoid long main-thread tasks 20 long tasks found
●Image elements have explicit `width` and `height`
●Network Requests
●Network Round Trip Times 150 ms
●Server Backend Latencies 340 ms
●Tasks
●Diagnostics
●Metrics
●Screenshot Thumbnails
●Final Screenshot
●Script Treemap Data
●Resources Summary
●Initial server response time was short Root document took 0 ms
●Avoid large layout shifts 2 layout shifts found
○INP breakdown
○Avoid non-composited animations
82

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.

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
span.mol-ads-cmp--nobr > span.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger > img.mol-ads-cmp--info span.mol-ads-cmp--nobr > span.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger > img.mol-ads-cmp--info
span.mol-ads-cmp--nobr > div.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger > img.mol-ads-cmp--info span.mol-ads-cmp--nobr > div.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger > img.mol-ads-cmp--info

Screen reader users rely on frame titles to describe the contents of frames. Learn more about frame titles.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
body > iframe#mol-ads-cmp-iframe body > iframe#mol-ads-cmp-iframe

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
h2.mol-ads-cmp--title > span.mol-ads-cmp--nobr > span.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger h2.mol-ads-cmp--title > span.mol-ads-cmp--nobr > span.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger
li > span.mol-ads-cmp--nobr > div.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger li > span.mol-ads-cmp--nobr > div.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger

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

Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. Learn more about heading order.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Humans article.Card > div.Card__Content > div.Card__CopyWrapper > h4.Card__Category
Physics article.Card > div.Card__Content > div.Card__CopyWrapper > h4.Card__Category
Weekend break article.Card > div.Card__Content > div.Card__CopyWrapper > h4.Card__Category

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
Physics section > article > h3.ThisWeeksMagazine__Category > a.ThisWeeksMagazine__CategoryLink
Mind section > article > h3.ThisWeeksMagazine__Category > a.ThisWeeksMagazine__CategoryLink
Space section > article > h3.ThisWeeksMagazine__Category > a.ThisWeeksMagazine__CategoryLink
Mathematics section > article > h3.ThisWeeksMagazine__Category > a.ThisWeeksMagazine__CategoryLink

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>`
●`[aria-*]` attributes have valid values
●`[aria-*]` attributes are valid and not misspelled
●Buttons have an accessible name
●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
●`[aria-hidden="true"]` elements do not contain focusable descendents
●Elements use only permitted ARIA attributes
●Background and foreground colors have a sufficient contrast ratio
●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.
●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
●Skip links are focusable.
●Document has a main landmark.
●Identical links have the same purpose.
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements have accessible names
○Deprecated ARIA roles were not used
○Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
○ARIA input fields have accessible names
○ARIA `meter` elements have accessible names
○ARIA `progressbar` elements have accessible names
○`[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
○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
○`<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.
○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.
73

Best Practices

User Experience

Image display dimensions should match natural aspect ratio. Learn more about image aspect ratio.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLAspect Ratio (Displayed)Aspect Ratio (Actual)
Piano End Banner div.PianoOverlay__BannerWrapper > div.PianoOverlay__EndBannerCentralColumn > a.PianoOverlay__EndBannerLink > img.PianoOverlay__EndBannerImage
/wp-content/uploads/2024/04/17102106/new-scientist-social...1276 x 85 (15.01)1200 x 627 (1.91)
Piano Exit Overlay Banner Mobile body > dialog#piano-central-overlay > a.PianoOverlay__ExitOverlayLink > img.PianoOverlay__ExitOverlayMobile
/wp-content/uploads/2024/04/17102106/new-scientist-social...300 x 400 (0.75)1200 x 627 (1.91)
Piano Exit Overlay Banner Desktop body > dialog#piano-central-overlay > a.PianoOverlay__ExitOverlayLink > img.PianoOverlay__ExitOverlayDesktop
/wp-content/uploads/2024/04/17102106/new-scientist-social...800 x 400 (2.00)1200 x 627 (1.91)
New Scientist. Science news and long reads from expert journalists, covering de… div.MarketingPanel__ContentWrapper > div.MarketingPanel__ImageWrapper > div.Image__Wrapper > img.Image
/wp-content/uploads/2026/04/15110004/nsl-launch-panel-mob...752 x 494 (1.52)800 x 602 (1.33)
New Scientist. Science news and long reads from expert journalists, covering de… div.MarketingPanel__CopyWrapper > div.MarketingPanel__LogoWrapper > div.Image__Wrapper > img.Image
/wp-content/uploads/2026/04/16122755/ns-live-stacked-ligh...306 x 260 (1.18)240 x 131 (1.83)

General

Deprecated APIs will eventually be removed from the browser. Learn more about deprecated APIs.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Deprecation / WarningSource
SharedStorage
cmp.dmgmediaprivacy.co.uk/ccpa/2.8.18-ccpa-46/iife/mol-ads-cmp.js line 5340, col 64
Unload event listeners are deprecated and will be removed.
dmg-libs.anm.co.uk/a/1.88.0/config.js line 1, col 235302
AttributionReporting
www.googletagmanager.com/gtag/js?id=AW-10897141567&cx=c&gtm=4e64h1 line 562, col 244
Topics
dmg-libs.anm.co.uk/a/1.88.0/222.js line 1, col 521056

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.newscientist.com/
Access to fetch at 'https://idsync.anm.co.uk/user-values/d7e774d5-ed09-463c-a83c-66af9d7938f3' from origin 'https://www.newscientist.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.
idsync.anm.co.uk/user-values/d7e774d5-ed09-463c-a83c-66af9d7938f3
Failed to load resource: net::ERR_FAILED
www.newscientist.com/api/v1/institutions-access
Failed to load resource: the server responded with a status of 400 ()
www.newscientist.com/api/v1/user-tokens
Failed to load resource: the server responded with a status of 401 ()
dmg-libs.anm.co.uk/a/1.88.0/config.js line 1, col 35451
Uncaught (in promise) TypeError: Failed to fetch
●Uses HTTPS
●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
●Serves images with appropriate resolution
●Page has the HTML doctype
●Properly defines charset
●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 DOM-based XSS with Trusted Types
●Detected JavaScript libraries
●Page has valid source maps
○Redirects HTTP traffic to HTTPS
○Mitigate clickjacking with XFO or CSP
85

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
section#piano-end-banner > div.PianoOverlay__BannerWrapper > div.PianoOverlay__EndBannerCentralColumn > a.PianoOverlay__EndBannerLink
body > dialog#piano-central-overlay > a.PianoOverlay__ExitOverlayLink
View more info div.mol-ads-cmp--button-privacy-link-group > div.mol-ads-ccpa--message > u > a

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
span.mol-ads-cmp--nobr > span.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger > img.mol-ads-cmp--info span.mol-ads-cmp--nobr > span.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger > img.mol-ads-cmp--info
span.mol-ads-cmp--nobr > div.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger > img.mol-ads-cmp--info span.mol-ads-cmp--nobr > div.mol-ads-cmp--tooltip > a.mol-ads-cmp--tooltip-trigger > img.mol-ads-cmp--info

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
●robots.txt is valid
●Document has a valid `hreflang`
●Document has a valid `rel=canonical`

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