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.

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.

Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Est Savings
z-m-static.xx.fbcdn.net/rsrc.php/yQ/r/-pkMfchyeAZ.woff2	40 ms
z-m-static.xx.fbcdn.net/rsrc.php/y2/r/6YirsaXqsap.woff2	20 ms

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

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.

URL	Transfer Size	Duration
z-m-static.xx.fbcdn.net/rsrc.php/v4/y-/r/aJd-UIzxCh_.js	67.2 KiB	2.7 s
z-m-static.xx.fbcdn.net/rsrc.php/v5/yn/l/0,cross/MAcSbRsyo3E.css	7.4 KiB	961 ms
z-m-static.xx.fbcdn.net/rsrc.php/v5/yz/l/0,cross/b8bT8K6wJb8.css	911 B	798 ms
z-m-static.xx.fbcdn.net/rsrc.php/v5/yU/l/0,cross/8LmiXDyZ1wv.css	412 B	798 ms
z-m-static.xx.fbcdn.net/rsrc.php/v5/yw/l/0,cross/NdI56imvkTb.css	962 B	798 ms
z-m-static.xx.fbcdn.net/rsrc.php/v5/yX/l/0,cross/xNRLBTJ11-F.css	1.2 KiB	798 ms

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: 2.3 s

URL	Time Spent
m.me/	822 ms
m.facebook.com/messages/?_rdr	875 ms
/login.php?next=https%3A%2F%2Fm.facebook.com%2Fmessages%2...	575 ms
/unified/login_via/app/?next=https%3A%2F%2Fm.facebook.com...	0.0 ms

Keep the server response time for the main document short because all other requests depend on it. Learn more about the Time to First Byte metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 683 ms

URL	Time Spent
/unified/login_via/app/?next=https%3A%2F%2Fm.facebook.com...	783 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: 1.7 s 225.8 KiB

URL	Transfer Size	Est Savings
z-m-static.xx.fbcdn.net/rsrc.php/v4/y_/r/PyXDsnpgJYe.js	274.0 KiB	156.1 KiB
z-m-static.xx.fbcdn.net/rsrc.php/v4iczx4/yF/l/en_US-j/SRUBP64C6E3.js	52.1 KiB	38.3 KiB
z-m-static.xx.fbcdn.net/rsrc.php/v4/y-/r/aJd-UIzxCh_.js	67.1 KiB	31.4 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
z-m-static.xx.fbcdn.net/rsrc.php/v4/y_/r/PyXDsnpgJYe.js	719 ms	432 ms	146 ms
/unified/login_via/app/?next=https%3A%2F%2Fm.facebook.com...	539 ms	255 ms	66 ms
Unattributable	484 ms	22 ms	0.0 ms
z-m-static.xx.fbcdn.net/rsrc.php/v4/y-/r/aJd-UIzxCh_.js	334 ms	236 ms	36 ms
z-m-static.xx.fbcdn.net/rsrc.php/v4iLl54/yI/l/en_US-j/LoNH-Sq6mqQ.js	110 ms	99 ms	5.9 ms
z-m-static.xx.fbcdn.net/rsrc.php/v4iczx4/yF/l/en_US-j/SRUBP64C6E3.js	65 ms	18 ms	27 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	1.1 s
Other	527 ms
Script Parsing & Compilation	309 ms
Style & Layout	211 ms
Garbage Collection	102 ms
Parse HTML & CSS	70 ms
Rendering	17 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
The page has an unload handler in the main frame.	Actionable
Pages with cache-control:no-store header cannot enter back/forward cache.	Actionable
Pages that use WebAuthetication API are not eligible for back/forward cache.	Pending browser support
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

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
Facebook from Meta `div.wbloks_1 > div.wbloks_1 > div.wbloks_1 > img.wbloks_1`	z-m-static.xx.fbcdn.net/rsrc.php/yU/r/0gFm6_6mwp0.webp
div.wbloks_1 > div.wbloks_1 > div.wbloks_1 > img.wbloks_1 `div.wbloks_1 > div.wbloks_1 > div.wbloks_1 > img.wbloks_1`	z-m-static.xx.fbcdn.net/rsrc.php/yh/r/iXKRnkL1VeD.webp
div.wbloks_1 > div.wbloks_1 > div.wbloks_1 > img.wbloks_1 `div.wbloks_1 > div.wbloks_1 > div.wbloks_1 > img.wbloks_1`	z-m-static.xx.fbcdn.net/rsrc.php/yS/r/kHeVcteEMil.webp
div.wbloks_1 > div.wbloks_1 > div.wbloks_1 > img.wbloks_1 `div.wbloks_1 > div.wbloks_1 > div.wbloks_1 > img.wbloks_1`	z-m-static.xx.fbcdn.net/rsrc.php/ys/r/lBaBOo8QfeT.webp

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

●Use efficient cache lifetimes

●Layout shift culprits

●Optimize DOM size

●Forced reflow

●Improve image delivery

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Reduce unused CSS

●Avoids enormous network payloads Total size was 900 KiB

●User Timing marks and measures 10 user timings

●Avoid long main-thread tasks 8 long tasks found

●Network Requests

●Network Round Trip Times 20 ms

●Server Backend Latencies 140 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Avoid large layout shifts 1 layout shift found

○INP breakdown

○LCP request discovery

○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 roles have required attributes that describe the state of the element to screen readers. Learn more about roles and required attributes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Facebook from Meta `div.wbloks_1 > div.wbloks_1 > div.wbloks_1 > img.wbloks_1`

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.

Names and labels

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
div#root > div._7om2 > div._4g34 > iframe#sem_pixel_iframe `div#root > div._7om2 > div._4g34 > iframe#sem_pixel_iframe`

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.

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.wbloks_11 `html.wbloks_11`

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

Best practices

Disabling zooming is problematic for users with low vision who rely on screen magnification to properly see the contents of a web page. Learn more about the viewport meta tag.

Why this matters

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

Source: MDN Permissions-Policy

Failing Elements
head > meta `head > meta`

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]` values are valid

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

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

●Image elements have `[alt]` attributes

●Form elements have associated labels

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

●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

●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

●All heading elements contain content.

●Uses ARIA roles only on compatible elements

●Elements with visible text labels have matching accessible names.

○`[accesskey]` values are unique

○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

○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

○Buttons have an accessible name

○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 a valid value for its `[lang]` attribute

○`<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

○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

○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>`.

○Image elements do not have `[alt]` attributes that are redundant text.

○Identical links have the same purpose.

○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

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 / Warning	Source
Unload event listeners are deprecated and will be removed.	z-m-static.xx.fbcdn.net/rsrc.php/v4/y-/r/aJd-UIzxCh_.js line 259, col 794

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.

Source Description

Source	Description
z-m-static.xx.fbcdn.net/rsrc.php/v4iczx4/yF/l/en_US-j/SRUBP64C6E3.js line 72, col 4235	`TypeError: Cannot read properties of undefined (reading 'getElementsByTagName') at Object.F [as scry] (https://z-m-static.xx.fbcdn.net/rsrc.php/v4iczx4/yF/l/en_US-j/SRUBP64C6E3.js:73:4236) at Object.ue [as scrollToHeader] (https://z-m-static.xx.fbcdn.net/rsrc.php/v4iczx4/yF/l/en_US-j/SRUBP64C6E3.js:86:4465) at u (https://z-m-static.xx.fbcdn.net/rsrc.php/v4/y_/r/PyXDsnpgJYe.js:71:253) at e (https://z-m-static.xx.fbcdn.net/rsrc.php/v4/y_/r/PyXDsnpgJYe.js:71:482)`

z-m-static.xx.fbcdn.net/rsrc.php/v4iczx4/yF/l/en_US-j/SRUBP64C6E3.js line 72, col 4235

TypeError: Cannot read properties of undefined (reading 'getElementsByTagName')
    at Object.F [as scry] (https://z-m-static.xx.fbcdn.net/rsrc.php/v4iczx4/yF/l/en_US-j/SRUBP64C6E3.js:73:4236)
    at Object.ue [as scrollToHeader] (https://z-m-static.xx.fbcdn.net/rsrc.php/v4iczx4/yF/l/en_US-j/SRUBP64C6E3.js:86:4465)
    at u (https://z-m-static.xx.fbcdn.net/rsrc.php/v4/y_/r/PyXDsnpgJYe.js:71:253)
    at e (https://z-m-static.xx.fbcdn.net/rsrc.php/v4/y_/r/PyXDsnpgJYe.js:71:482)

Source maps translate minified code to the original source code. This helps developers debug in production. In addition, Lighthouse is able to provide further insights. Consider deploying source maps to take advantage of these benefits. Learn more about source maps.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL
z-m-static.xx.fbcdn.net/rsrc.php/v4/y_/r/PyXDsnpgJYe.js

●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

●Displays images with correct aspect ratio

●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

●Mitigate DOM-based XSS with Trusted Types

○Redirects HTTP traffic to HTTPS

○Ensure proper origin isolation with COOP

○Mitigate clickjacking with XFO or CSP

○Detected JavaScript libraries

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`