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 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
sourcepoint.theguardian.com/Notice.b4712.js	3600.0 s	92.7 KiB
sourcepoint.theguardian.com/unified/wrapperMessagingWithoutDetection.js	3600.0 s	42.4 KiB
/fonts/guss-webfonts/GuardianTextSansWeb/GuardianTextSans...	302400.0 s	38.8 KiB
/fonts/guss-webfonts/GuardianTextSansWeb/GuardianTextSans...	302400.0 s	35.7 KiB
sourcepoint.theguardian.com/Notice.30929.css	3600.0 s	6.8 KiB
interactive.guim.co.uk/fonts/garnett/GTGuardianTitlepiece-Bold.woff2	604800.0 s	26.2 KiB
sourcepoint.theguardian.com/polyfills.01516.js	3600.0 s	2.4 KiB
/polyfill.io/v3/polyfill.min.js?rum=0&features=es6%2Ces7%...	604800.0 s	0 B

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

items: [map[reflowTime:52.019 source:map[type:text value:[unattributed]]]]

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
An image of biohazard tape superimposed on a picture of the deck of a cruise sh… `div.dcr-8ierls > div.dcr-kkt25y > picture.dcr-19yn8oe > img.dcr-l300o4`	/img/media/be10553ece19f10d6e94c69bc7321e7643a0c8f8/0_164...	51.0 KiB	23.2 KiB
A naval destroyer escorts a large cargo tanker silhouetted against a golden sun… `div.dcr-1ummryo > div.dcr-1iak74q > picture.dcr-1ydxyte > img.dcr-l300o4`	/img/media/6320ff0598aba867cf2dfac80c310c4f238210c4/246_0...	39.1 KiB	17.8 KiB
Kyiv motorists stop their cars and observe a one-minute silence daily at 9am to… `div.dcr-1ummryo > div.dcr-19y4zys > picture.dcr-1ydxyte > img.dcr-l300o4`	/img/media/8d117abca578ce22e5cc08f482cc94b2e64c3ddd/745_0...	34.4 KiB	15.7 KiB

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-2-IMG

nodeLabel: Kyiv motorists stop their cars and observe a one-minute silence daily at 9am to…

path: 1,HTML,1,BODY,13,MAIN,1,SECTION,3,DIV,0,UL,0,LI,0,DIV,0,DIV,1,DIV,0,DIV,0,PICTURE,8,IMG

selector: div.dcr-1ummryo > div.dcr-19y4zys > picture.dcr-1ydxyte > img.dcr-l300o4

snippet: <img alt="Kyiv motorists stop their cars and observe a one-minute silence daily at 9…" src="https://i.guim.co.uk/img/media/8d117abca578ce22e5cc08f482cc94b2e64c3ddd/74…" loading="eager" data-chromatic="ignore" class="dcr-l300o4">

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

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.

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: 769 ms

URL	Time Spent
www.theguardian.com/	769 ms
www.theguardian.com/international	0.0 ms

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.

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: 600 ms 150.6 KiB

URL	Transfer Size	Est Savings
sourcepoint.theguardian.com/Notice.b4712.js	92.2 KiB	62.4 KiB
assets.guim.co.uk/assets/index.client.web.de6f83cc1d33c894266a.js	167.4 KiB	54.3 KiB
assets.guim.co.uk/commercial/866ff7c3703314d6cbd7/graun.standalone.commercial.js	55.9 KiB	33.9 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
www.theguardian.com/international	1.2 s	41 ms	11 ms
sourcepoint.theguardian.com/Notice.b4712.js	918 ms	585 ms	48 ms
Unattributable	802 ms	9.5 ms	0.0 ms
assets.guim.co.uk/assets/index.client.web.de6f83cc1d33c894266a.js	397 ms	365 ms	1.0 ms
sourcepoint.theguardian.com/unified/wrapperMessagingWithoutDetection.js	285 ms	225 ms	21 ms
assets.guim.co.uk/assets/Metrics-island.client.web.a76a7485e0aad868e34a.js	236 ms	231 ms	1.4 ms
assets.guim.co.uk/assets/0.client.web.fcf0e994afa8386c9dd1.js	154 ms	139 ms	14 ms
assets.guim.co.uk/assets/Titlepiece-island.client.web.9ec4f934363cb29976ef.js	146 ms	138 ms	7.8 ms
assets.guim.co.uk/assets/1958.client.web.a05ac43a9aff7a0f2fd8.js	115 ms	105 ms	9.3 ms
/unified/4.40.1/gdpr-tcf.27718c8cb9d29947d2c1.bundle.js	75 ms	52 ms	22 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	2.2 s
Style & Layout	914 ms
Other	894 ms
Parse HTML & CSS	424 ms
Script Parsing & Compilation	196 ms
Rendering	131 ms
Garbage Collection	66 ms

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.dcr-1ja1q18 > div.dcr-vbvtsi > div.dcr-49rh6p > img `div.dcr-1ja1q18 > div.dcr-vbvtsi > div.dcr-49rh6p > img`	api.nextgen.guardianapps.co.uk/crosswords/cryptic/30000.svg

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 breakdown

●Modern HTTP

●Render blocking requests

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Reduce unused CSS

●Avoids enormous network payloads Total size was 971 KiB

●User Timing marks and measures 130 user timings

●Avoid long main-thread tasks 19 long tasks found

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 160 ms

●Server Backend Latencies 160 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 30 ms

●Avoid large layout shifts 2 layout shifts found

○INP breakdown

○Avoid non-composited animations

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.

ARIA

Some ARIA parent roles must contain specific child roles to perform their intended accessibility functions. Learn more about roles and required children elements.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
News Opinion Sport Culture Lifestyle Search input google-search Search Support … `div#header-expanded-menu > div.dcr-1srap2j > div.dcr-1ndqjmr > ul.dcr-6sl420`

These are opportunities to improve the usage of ARIA in your application which may enhance the experience for users of assistive technology, like a screen reader.

Tables and lists

Screen readers have a specific way of announcing lists. Ensuring proper list structure aids screen reader output. Learn more about proper list structure.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
‘Odds not in our favour’ Doomsday Clock setters on the future of humanity Infec… `div.dcr-1ykr3rf > gu-island > div.dcr-1beghel > ul.dcr-1tj3ydw`

These are opportunities to improve the experience of reading tabular or list data using assistive technology, like a screen reader.

○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]`s are contained by their required parent element

●`[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.

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

●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

●Background and foreground colors have a sufficient contrast ratio

●Document has a `<title>` element

●`<frame>` or `<iframe>` elements have a title

●`<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

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

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

●Touch targets have sufficient size and spacing.

●Heading elements appear in a sequentially-descending order

●Document has a main landmark.

●Deprecated ARIA roles were not used

●ARIA IDs are unique

●No form fields have multiple labels

●`<video>` elements contain a `<track>` element with `[kind="captions"]`

●Uses ARIA roles only on compatible elements

●Identical links have the same purpose.

○`[accesskey]` values are unique

○ARIA input fields have accessible names

○ARIA `meter` elements have accessible names

○ARIA `progressbar` elements have accessible names

○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

○`<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

○Tables have different content in the summary attribute and `<caption>`.

○All heading elements contain content.

○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.

100

Best Practices

●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

●Serves images with appropriate resolution

●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

●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

○Use a strong HSTS policy

○Mitigate clickjacking with XFO or CSP

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.

Content Best Practices

Descriptive link text helps search engines understand your content. Learn how to make links more accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Link destination	Link Text
www.theguardian.com/info/2024/feb/28/what-is-the-deeply-read-list	Learn more

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.

Crawling and Indexing

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.

Line #	Content	Error
103	`License: https://theguardian.com/license.xml`	`Unknown directive`

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

○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 are crawlable

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`