Skip to content
Audit Complete

Results for https://www.rust-lang.org

Visit site
Singapore Singapore · Singapore Completed: Apr 4, 2026 16:48 UTC

Mobile 375 × 812

Screenshot of the audited page (Mobile 375×812)

Desktop 1440 × 900

Screenshot of the audited page (Desktop 1440×900)
C78

Site Health

Score: 78 / 100

Based on 8 categories, 0 sections

How is this calculated?

The overall score is a weighted average of individual category scores. Categories with more impact on user experience and security carry more weight.

Performance 25%Security 25%Accessibility 15%SEO 10%Infrastructure 10%Compliance 8%Content 5%Sustainability 2%

Weights reflect general web best practices. Individual needs may differ.

Top Priorities (5)

1

Content-Security-Policy header is missing

Security › Security Headers
2

HSTS header is missing

Security › Security Headers
3

No Content-Security-Policy header found

Security › Content Security Policy
4

Cross-Origin-Embedder-Policy header is missing

Security › Security Headers
5

Cross-Origin-Opener-Policy header is missing

Security › Security Headers
BeaverCheck badge
Embed this badge
[![BeaverCheck](https://beavercheck.com/badge?url=https%3A%2F%2Fwww.rust-lang.org)](https://beavercheck.com/results/ab30bb16-f2ee-48c4-b96d-572d3fb4874c)
<a href="https://beavercheck.com/results/ab30bb16-f2ee-48c4-b96d-572d3fb4874c"><img src="https://beavercheck.com/badge?url=https%3A%2F%2Fwww.rust-lang.org" alt="BeaverCheck Score"></a>
https://beavercheck.com/badge?url=https%3A%2F%2Fwww.rust-lang.org

This badge auto-updates with your latest scan result.

Was this report useful?

Thanks for your feedback!

Lighthouse Scores

Industry-standard audits powered by Google Lighthouse.

97
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
87
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

Core Web Vitals

Key metrics that affect user experience.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

1.97 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

1.97 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

0 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.001

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

2.60 s

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

1.97 s

Detailed Report

Audit breakdown by category with detailed findings.

97

Performance

Insights

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

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

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

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

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.

headings: [map[key:source label:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]
items: [map[reflowTime:56.924 source:map[type:text value:[unattributed]]]]

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.

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
value: No additional origins are good candidates for preconnecting

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.

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

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.

Estimated savings: 0.0 ms 13.7 KiB
URLTransfer SizeEst Savings
rust-lang.org/static/styles/vendor_10880690442070639967.css14.0 KiB13.7 KiB

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

URL
Bluesky div.flex > div.flex > a > img
rust-lang.org/static/images/bluesky.svg
terminal div.flex-none > div.flex > div.v-top > img.mw3
rust-lang.org/static/images/cli.svg
gear with puzzle piece elements div.flex-none > div.flex > div.v-top > img.mw3
rust-lang.org/static/images/webassembly.svg
a cloud with nodes div.flex-none > div.flex > div.v-top > img.mw3
rust-lang.org/static/images/networking.svg
an embedded device chip div.flex-none > div.flex > div.v-top > img.mw3
rust-lang.org/static/images/embedded.svg
github logo div.flex > div.flex > a > img
rust-lang.org/static/images/github.svg
youtube logo div.flex > div.flex > a > img.pv2
rust-lang.org/static/images/youtube.svg
Mastodon div.flex > div.flex > a > img
rust-lang.org/static/images/mastodon.svg
Rust Logo nav.flex > div.brand > a.brand > img.v-mid
rust-lang.org/static/images/rust-logo-blk.svg

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

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

Estimated savings: 752 ms
URLTime Spent
www.rust-lang.org/752 ms
rust-lang.org/0.0 ms
Time to Interactive 2.0 s
Layout shift culprits
Optimize DOM size
Font display
Improve image delivery
LCP breakdown
Modern HTTP
Optimize viewport for mobile
Max Potential First Input Delay 20 ms
Minify CSS
Minify JavaScript
Reduce unused JavaScript
Avoids enormous network payloads Total size was 132 KiB
JavaScript execution time 0.0 s
Minimizes main-thread work 0.8 s
Avoid long main-thread tasks 2 long tasks found
Page didn't prevent back/forward cache restoration
Network Requests
Network Round Trip Times 0 ms
Server Backend Latencies 10 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
LCP request discovery
User Timing marks and measures
Avoid non-composited animations
87

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.

Failing Elements
Version 1.94.1 div.flex > div.w-30-l > p.tc > a.download-link

Low-contrast text is difficult or impossible for many users to read. Link text that is discernible improves the experience for users with low vision. Learn how to make links distinguishable.

Failing Elements
File an issue! div.w-100 > div.attribution > p > a
previous website div.w-100 > div.attribution > p > a

These are opportunities to improve the legibility of your content.

Interactive controls are keyboard focusable
Interactive elements indicate their purpose and state
The page has a logical tab order
Visual order on the page follows DOM order
User focus is not accidentally trapped in a region
The user's focus is directed to new content added to the page
HTML5 landmark elements are used to improve navigation
Offscreen content is hidden from assistive technology
Custom controls have associated labels
Custom controls have ARIA roles
`[aria-hidden="true"]` is not present on the document `<body>`
Image elements have `[alt]` attributes
`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
Select elements have associated label elements.
Document has a `<title>` element
`<html>` element has a `[lang]` attribute
`<html>` element has a valid value for its `[lang]` attribute
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
Touch targets have sufficient size and spacing.
Heading elements appear in a sequentially-descending order
Document has a main landmark.
`[accesskey]` values are unique
`[aria-*]` attributes match their roles
`button`, `link`, and `menuitem` elements have accessible names
ARIA attributes are used as specified for the element's role
Deprecated ARIA roles were not used
Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
`[aria-hidden="true"]` elements do not contain focusable descendents
ARIA input fields have accessible names
ARIA `meter` elements have accessible names
ARIA `progressbar` elements have accessible names
Elements use only permitted ARIA attributes
`[role]`s have all required `[aria-*]` attributes
Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.
`[role]`s are contained by their required parent element
`[role]` values are valid
Elements with the `role=text` attribute do not have focusable descendents.
ARIA toggle fields have accessible names
ARIA `tooltip` elements have accessible names
ARIA `treeitem` elements have accessible names
`[aria-*]` attributes have valid values
`[aria-*]` attributes are valid and not misspelled
Buttons have an accessible name
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
Form elements have associated labels
The document does not use `<meta http-equiv="refresh">`
`<object>` elements have alternate text
Skip links are focusable.
No element has a `[tabindex]` value greater than 0
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.
Identical links have the same purpose.
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
Use a strong HSTS policy
Ensure proper origin isolation with COOP
Mitigate clickjacking with XFO or CSP
Mitigate DOM-based XSS with Trusted Types
Page has valid source maps
Redirects HTTP traffic to HTTPS
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
Image elements have `[alt]` attributes
Document has a valid `hreflang`
robots.txt is valid
Document has a valid `rel=canonical`

Lighthouse Scores

Industry-standard audits powered by Google Lighthouse. — Desktop

100
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
94
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

Core Web Vitals

Key metrics that affect user experience. — Desktop

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

535 ms

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

586 ms

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

0 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.003

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

535 ms

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

586 ms

Detailed Report

Audit breakdown by category with detailed findings.

100

Performance

Insights

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

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

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

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

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.

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
value: No additional origins are good candidates for preconnecting

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.

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

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.

Estimated savings: 40 ms 13.3 KiB
URLTransfer SizeEst Savings
rust-lang.org/static/styles/vendor_10880690442070639967.css14.0 KiB13.3 KiB

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

URL
Bluesky div.flex > div.flex > a > img
rust-lang.org/static/images/bluesky.svg
terminal div.flex-none > div.flex > div.v-top > img.mw3
rust-lang.org/static/images/cli.svg
gear with puzzle piece elements div.flex-none > div.flex > div.v-top > img.mw3
rust-lang.org/static/images/webassembly.svg
a cloud with nodes div.flex-none > div.flex > div.v-top > img.mw3
rust-lang.org/static/images/networking.svg
an embedded device chip div.flex-none > div.flex > div.v-top > img.mw3
rust-lang.org/static/images/embedded.svg
github logo div.flex > div.flex > a > img
rust-lang.org/static/images/github.svg
youtube logo div.flex > div.flex > a > img.pv2
rust-lang.org/static/images/youtube.svg
Mastodon div.flex > div.flex > a > img
rust-lang.org/static/images/mastodon.svg
Rust Logo nav.flex > div.brand > a.brand > img.v-mid
rust-lang.org/static/images/rust-logo-blk.svg

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

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

Estimated savings: 201 ms
URLTime Spent
www.rust-lang.org/201 ms
rust-lang.org/0.0 ms
Layout shift culprits
Optimize DOM size
Font display
Forced reflow
Improve image delivery
LCP breakdown
Modern HTTP
Optimize viewport for mobile
Time to Interactive 0.6 s
Max Potential First Input Delay 20 ms
Minify CSS
Minify JavaScript
Reduce unused JavaScript
Avoids enormous network payloads Total size was 132 KiB
JavaScript execution time 0.0 s
Minimizes main-thread work 0.2 s
Page didn't prevent back/forward cache restoration
Network Requests
Network Round Trip Times 0 ms
Server Backend Latencies 0 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
LCP request discovery
User Timing marks and measures
Avoid long main-thread tasks
Avoid non-composited animations
94

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. Link text that is discernible improves the experience for users with low vision. Learn how to make links distinguishable.

Failing Elements
File an issue! div.w-100 > div.attribution > p > a
previous website div.w-100 > div.attribution > p > a

These are opportunities to improve the legibility of your content.

Interactive controls are keyboard focusable
Interactive elements indicate their purpose and state
The page has a logical tab order
Visual order on the page follows DOM order
User focus is not accidentally trapped in a region
The user's focus is directed to new content added to the page
HTML5 landmark elements are used to improve navigation
Offscreen content is hidden from assistive technology
Custom controls have associated labels
Custom controls have ARIA roles
`[aria-hidden="true"]` is not present on the document `<body>`
Image elements have `[alt]` attributes
`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
Select elements have associated label elements.
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 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
Touch targets have sufficient size and spacing.
Heading elements appear in a sequentially-descending order
Document has a main landmark.
`[accesskey]` values are unique
`[aria-*]` attributes match their roles
`button`, `link`, and `menuitem` elements have accessible names
ARIA attributes are used as specified for the element's role
Deprecated ARIA roles were not used
Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
`[aria-hidden="true"]` elements do not contain focusable descendents
ARIA input fields have accessible names
ARIA `meter` elements have accessible names
ARIA `progressbar` elements have accessible names
Elements use only permitted ARIA attributes
`[role]`s have all required `[aria-*]` attributes
Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.
`[role]`s are contained by their required parent element
`[role]` values are valid
Elements with the `role=text` attribute do not have focusable descendents.
ARIA toggle fields have accessible names
ARIA `tooltip` elements have accessible names
ARIA `treeitem` elements have accessible names
`[aria-*]` attributes have valid values
`[aria-*]` attributes are valid and not misspelled
Buttons have an accessible name
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
Form elements have associated labels
The document does not use `<meta http-equiv="refresh">`
`<object>` elements have alternate text
Skip links are focusable.
No element has a `[tabindex]` value greater than 0
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.
Identical links have the same purpose.
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
Use a strong HSTS policy
Ensure proper origin isolation with COOP
Mitigate clickjacking with XFO or CSP
Mitigate DOM-based XSS with Trusted Types
Page has valid source maps
Redirects HTTP traffic to HTTPS
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
Image elements have `[alt]` attributes
Document has a valid `hreflang`
robots.txt is valid
Document has a valid `rel=canonical`

Send Feedback