C — https://www.youtube.com | BeaverCheck Audit

Site Health

Score: 73 / 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)

'unsafe-eval' found in script source

Security › Content Security Policy

'unsafe-inline' found in script source

Security › Content Security Policy

2 button(s) with no accessible text

Accessibility › Link & Button Quality

2 image(s) missing alt attribute

Accessibility › Alt Text Quality

2 image-in-link without alt text

Accessibility › Alt Text Quality

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Markdown

[![BeaverCheck](https://beavercheck.com/badge?url=https%3A%2F%2Fwww.youtube.com)](https://beavercheck.com/results/ecd3cb79-33fe-a132-c7b8-1c047819da59)

HTML

<a href="https://beavercheck.com/results/ecd3cb79-33fe-a132-c7b8-1c047819da59"><img src="https://beavercheck.com/badge?url=https%3A%2F%2Fwww.youtube.com" alt="BeaverCheck Score"></a>

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Lighthouse Scores

Industry-standard audits powered by Google Lighthouse.

Performance

Accessibility

100

Best Practices

100

SEO

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.

6.31 s

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

6.94 s

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

916 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.

6.31 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.

11.51 s

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.

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.

URL	Transfer Size	Duration
/s/_/ytmweb/_/js/k=ytmweb.c3_base.en_US.H8Ls_CPT03Y.2021....	433.5 KiB	3.6 s
m.youtube.com/static/r/84ceb080/scheduler.vflset/scheduler.js	3.1 KiB	468 ms
m.youtube.com/static/r/84ceb080/fetch_polyfill.vflset/fetch_polyfill.js	2.6 KiB	468 ms
/s/_/ytmweb/_/ss/k=ytmweb.c3_base.vrvbSQWciDc.L.W.O/am=AA...	122.8 KiB	2.0 s

A long cache lifetime can speed up repeat visits to your page. Learn more about caching.

Request	Cache TTL	Transfer Size
static.doubleclick.net/instream/ad_status.js	900.0 s	495 B

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.

Estimated savings: 779 ms

URL	Time Spent
www.youtube.com/	779 ms
m.youtube.com/	0.0 ms

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.

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.

TTI

Diagnostics

Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.

Estimated savings: 580 ms 180.1 KiB

URL	Transfer Size	Est Savings
/s/_/ytmweb/_/ss/k=ytmweb.c3_base.vrvbSQWciDc.L.W.O/am=AA...	122.8 KiB	120.0 KiB
m.youtube.com/s/player/57fefa84/mobile-polymer-player-svg-ias-mweb.css	60.1 KiB	60.1 KiB

Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.

Estimated savings: 1.2 s 598.4 KiB

URL	Transfer Size	Est Savings
m.youtube.com/s/player/57fefa84/player-plasma-es6-en_US.vflset/base.js	415.6 KiB	306.8 KiB
/s/_/ytmweb/_/js/k=ytmweb.c3_base.en_US.H8Ls_CPT03Y.2021....	433.5 KiB	232.3 KiB
/s/_/ytmweb/_/js/k=ytmweb.c3_base.en_US.H8Ls_CPT03Y.2021....	77.4 KiB	59.3 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.

URL	Total CPU Time	Script Evaluation	Script Parse
/s/_/ytmweb/_/js/k=ytmweb.c3_base.en_US.H8Ls_CPT03Y.2021....	1.7 s	1.4 s	178 ms
Unattributable	1.0 s	204 ms	0.0 ms
m.youtube.com/	558 ms	162 ms	63 ms
m.youtube.com/s/player/57fefa84/player-plasma-es6-en_US.vflset/base.js	259 ms	102 ms	153 ms
/s/_/ytmweb/_/js/k=ytmweb.c3_base.en_US.H8Ls_CPT03Y.2021....	178 ms	114 ms	43 ms
m.youtube.com/static/r/84ceb080/scheduler.vflset/scheduler.js	168 ms	133 ms	2.9 ms
www.google.com/js/th/PF32M1WFt3Opj6X4HHxBvSVo4hj3YoJbcs9XKKWIAD0.js	114 ms	106 ms	7.1 ms
/s/_/ytmweb/_/js/k=ytmweb.c3_base.en_US.H8Ls_CPT03Y.2021....	97 ms	87 ms	7.8 ms
m.youtube.com/s/player/57fefa84/mobile-polymer-player-svg-ias-mweb.css	95 ms	0.0 ms	0.0 ms
/s/_/ytmweb/_/js/k=ytmweb.c3_base.en_US.H8Ls_CPT03Y.2021....	67 ms	57 ms	1.1 ms
/s/_/ytmweb/_/js/k=ytmweb.c3_base.en_US.H8Ls_CPT03Y.2021....	59 ms	50 ms	1.0 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

Category	Time Spent
Script Evaluation	3.3 s
Other	1.1 s
Script Parsing & Compilation	460 ms
Parse HTML & CSS	187 ms
Style & Layout	145 ms
Garbage Collection	87 ms
Rendering	26 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

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

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

●Layout shift culprits

●Optimize DOM size

●Font display

●Forced reflow

●Improve image delivery

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Avoids enormous network payloads Total size was 1,295 KiB

●User Timing marks and measures 30 user timings

●Avoid long main-thread tasks 20 long tasks found

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

●Network Requests

●Network Round Trip Times 30 ms

●Server Backend Latencies 50 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 60 ms

●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.

Contrast

Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.

Failing Elements
Search YouTube `ytm-search-bar-entry-point-view-model > div.search-bar-entry-point-buttons > div.search-bar-entry-point-button > span.search-bar-entry-point-text`

These are opportunities to improve the legibility of your content.

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.

Failing Elements
head > meta `head > meta`

One main landmark helps screen reader users navigate a web page. Learn more about landmarks.

Failing Elements
html `html`

These items highlight common accessibility best practices.

○Interactive controls are keyboard focusable

○Interactive elements indicate their purpose and state

○The page has a logical tab order

○Visual order on the page follows DOM order

○User focus is not accidentally trapped in a region

○The user's focus is directed to new content added to the page

○HTML5 landmark elements are used to improve navigation

○Offscreen content is hidden from assistive technology

○Custom controls have associated labels

○Custom controls have ARIA roles

●`[aria-*]` attributes match their roles

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

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

●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

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

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

●Buttons have an accessible name

●Image elements have `[alt]` attributes

●`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

●Elements with the `role=text` attribute do not have focusable descendents.

●Document has a `<title>` element

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

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

●Touch targets have sufficient size and spacing.

●Heading elements appear in a sequentially-descending order

●Deprecated ARIA roles were not used

●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

○ARIA toggle fields have accessible names

○ARIA `tooltip` elements have accessible names

○ARIA `treeitem` elements have accessible names

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

○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.

○Definition list items are wrapped in `<dl>` elements

○ARIA IDs are unique

○No form fields have multiple labels

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

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

○Input buttons have discernible text.

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

○Form elements have associated labels

○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.

○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.

○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

General

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.

URL
m.youtube.com/s/player/57fefa84/player-plasma-es6-en_US.vflset/base.js
/s/_/ytmweb/_/js/k=ytmweb.c3_base.en_US.H8Ls_CPT03Y.2021....
www.google.com/js/th/PF32M1WFt3Opj6X4HHxBvSVo4hj3YoJbcs9XKKWIAD0.js

●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

●Use a strong HSTS policy

●Ensure proper origin isolation with COOP

●Detected JavaScript libraries

○Redirects HTTP traffic to HTTPS

○Ensure CSP is effective against XSS attacks

○Mitigate clickjacking with XFO or CSP

○Mitigate DOM-based XSS with Trusted Types

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`

Lighthouse Scores

Industry-standard audits powered by Google Lighthouse. — Desktop

Performance

Accessibility

Best Practices

SEO

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.

942 ms

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

3.70 s

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

804 ms

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

0.028

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

3.01 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.

4.54 s

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.

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

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

items: [map[reflowTime:36.799 source:map[column:91 line:1934 type:source-location url:https://www.youtube.com/s/_/ytmainappweb/_/js/k=ytmainappweb.kevlar_base.en_US.zRTiNATFin8.es5.O/am=AAAAAgAAIAE/d=1/br=1/rs=AGKMywHgEkn2QsaXPRgwZ5kiaKEgDzy-mQ/m=kevlar_base_module,kevlar_main_module 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:0.547 source:map[column:483 line:93 type:source-location url:https://www.youtube.com/s/desktop/0203efec/jsbin/web-animations-next-lite.min.vflset/web-animations-next-lite.min.js urlProvider:network]] map[reflowTime:0.184 source:map[column:92 line:94 type:source-location url:https://www.youtube.com/s/desktop/0203efec/jsbin/web-animations-next-lite.min.vflset/web-animations-next-lite.min.js urlProvider:network]] map[reflowTime:0.305 source:map[column:11795 line:18 type:source-location url:https://www.youtube.com/ urlProvider:network]] map[reflowTime:17.89 source:map[column:23656 line:20 type:source-location url:https://www.youtube.com/ urlProvider:network]] map[reflowTime:20.216 source:map[type:text value:[unattributed]]] map[reflowTime:2.196 source:map[column:222 line:30446 type:source-location url:https://www.youtube.com/s/_/ytmainappweb/_/js/k=ytmainappweb.kevlar_base.en_US.zRTiNATFin8.es5.O/am=AAAAAgAAIAE/d=1/br=1/rs=AGKMywHgEkn2QsaXPRgwZ5kiaKEgDzy-mQ/m=kevlar_base_module,kevlar_main_module urlProvider:network]] map[reflowTime:0.988 source:map[column:80 line:30467 type:source-location url:https://www.youtube.com/s/_/ytmainappweb/_/js/k=ytmainappweb.kevlar_base.en_US.zRTiNATFin8.es5.O/am=AAAAAgAAIAE/d=1/br=1/rs=AGKMywHgEkn2QsaXPRgwZ5kiaKEgDzy-mQ/m=kevlar_base_module,kevlar_main_module urlProvider:network]] map[reflowTime:2.16 source:map[column:352 line:5760 type:source-location url:https://www.youtube.com/s/_/ytmainappweb/_/js/k=ytmainappweb.kevlar_base.en_US.zRTiNATFin8.es5.O/am=AAAAAgAAIAE/d=1/br=1/rs=AGKMywHgEkn2QsaXPRgwZ5kiaKEgDzy-mQ/m=kevlar_base_module,kevlar_main_module urlProvider:network]] map[reflowTime:0.158 source:map[column:184 line:3748 type:source-location url:https://www.youtube.com/s/_/ytmainappweb/_/js/k=ytmainappweb.kevlar_base.en_US.zRTiNATFin8.es5.O/am=AAAAAgAAIAE/d=1/br=1/rs=AGKMywHgEkn2QsaXPRgwZ5kiaKEgDzy-mQ/m=kevlar_base_module,kevlar_main_module urlProvider:network]] map[reflowTime:36.799 source:map[column:400 line:30450 type:source-location url:https://www.youtube.com/s/_/ytmainappweb/_/js/k=ytmainappweb.kevlar_base.en_US.zRTiNATFin8.es5.O/am=AAAAAgAAIAE/d=1/br=1/rs=AGKMywHgEkn2QsaXPRgwZ5kiaKEgDzy-mQ/m=kevlar_base_module,kevlar_main_module urlProvider:network]]]

Each subpart has specific improvement strategies. Ideally, most of the LCP time should be spent on loading the resources, not within delays.

headings: [map[key:label label:Subpart valueType:text] map[key:duration label:Duration valueType:ms]]

items: [map[duration:160.72 label:Time to first byte subpart:timeToFirstByte] map[duration:2519.334 label:Element render delay subpart:elementRenderDelay]]

lhId: page-0-H2

nodeLabel: Try searching to get started

path: 1,HTML,1,BODY,4,YTD-APP,8,DIV,4,YTD-PAGE-MANAGER,3,YTD-BROWSE,13,YTD-TWO-COLUMN-BROWSE-RESULTS-RENDERER,3,DIV,0,YTD-RICH-GRID-RENDERER,7,DIV,0,YTD-RICH-SECTION-RENDERER,3,DIV,0,YTD-FEED-NUDGE-RENDERER,3,DIV,1,DIV,1,DIV,0,H2

selector: div#dismissible > div#content-wrapper > div#text-container > h2#title-container

snippet: <h2 id="title-container" class="style-scope ytd-feed-nudge-renderer" aria-label="Try searching to get started">

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.

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.

URL	Transfer Size	Duration
www.youtube.com/s/desktop/0203efec/jsbin/spf.vflset/spf.js	11.9 KiB
www.youtube.com/s/desktop/0203efec/jsbin/network.vflset/network.js	4.9 KiB
/s/_/ytmainappweb/_/ss/k=ytmainappweb.kevlar_base.uWbmUbF...	274.8 KiB	480 ms
/css2?family=Roboto:wght@300;400;500;700&family=YouTube+S...	15.4 KiB	342 ms
/s/desktop/0203efec/jsbin/web-animations-next-lite.min.vf...	13.8 KiB
/s/desktop/0203efec/jsbin/www-i18n-constants-en_US.vflset...	1.5 KiB
/s/desktop/0203efec/jsbin/intersection-observer.min.vflse...	2.0 KiB
/s/desktop/0203efec/jsbin/custom-elements-es5-adapter.vfl...	781 B
/s/desktop/0203efec/jsbin/webcomponents-sd.vflset/webcomp...	21.0 KiB
www.youtube.com/s/desktop/0203efec/jsbin/scheduler.vflset/scheduler.js	3.1 KiB
www.youtube.com/s/desktop/0203efec/cssbin/www-onepick.css	338 B
/s/desktop/0203efec/cssbin/www-main-desktop-home-page-ske...	1.3 KiB
/s/desktop/0203efec/cssbin/www-main-desktop-watch-page-sk...	1.4 KiB

A long cache lifetime can speed up repeat visits to your page. Learn more about caching.

Request	Cache TTL	Transfer Size
www.gstatic.com/eureka/clank/146/cast_sender.js	86400.0 s	13.1 KiB
static.doubleclick.net/instream/ad_status.js	900.0 s	495 B

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

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

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.

TTI

Diagnostics

Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.

Estimated savings: 240 ms 337.6 KiB

URL	Transfer Size	Est Savings
/s/_/ytmainappweb/_/ss/k=ytmainappweb.kevlar_base.uWbmUbF...	274.4 KiB	266.0 KiB
www.youtube.com/s/player/57fefa84/www-player.css	56.7 KiB	56.7 KiB
/css2?family=Roboto:wght@300;400;500;700&family=YouTube+S...	14.9 KiB	14.9 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.

Estimated savings: 880 ms 1.6 MiB

URL	Transfer Size	Est Savings
/s/_/ytmainappweb/_/js/k=ytmainappweb.kevlar_base.en_US.z...	1.8 MiB	1.1 MiB
www.youtube.com/s/player/57fefa84/player_es6.vflset/en_US/base.js	637.7 KiB	474.9 KiB
www.youtube.com/s/player/57fefa84/player_es6.vflset/en_US/remote.js	34.3 KiB	26.8 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.

URL	Total CPU Time	Script Evaluation	Script Parse
/s/_/ytmainappweb/_/js/k=ytmainappweb.kevlar_base.en_US.z...	1.8 s	1.4 s	256 ms
Unattributable	577 ms	167 ms	0.0 ms
/s/desktop/0203efec/jsbin/web-animations-next-lite.min.vf...	535 ms	426 ms	1.3 ms
www.youtube.com/s/player/57fefa84/player_es6.vflset/en_US/base.js	289 ms	195 ms	73 ms
www.youtube.com/	243 ms	22 ms	24 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

Category	Time Spent
Script Evaluation	2.7 s
Other	514 ms
Script Parsing & Compilation	372 ms
Style & Layout	189 ms
Parse HTML & CSS	177 ms
Garbage Collection	68 ms
Rendering	26 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

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

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

URL	Transfer Size
/s/_/ytmainappweb/_/js/k=ytmainappweb.kevlar_base.en_US.z...	1.8 MiB
www.youtube.com/s/player/57fefa84/player_es6.vflset/en_US/base.js	637.7 KiB
/s/_/ytmainappweb/_/ss/k=ytmainappweb.kevlar_base.uWbmUbF...	274.8 KiB
www.youtube.com/	76.4 KiB
www.youtube.com/s/player/57fefa84/www-player.css	56.7 KiB
fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2	36.7 KiB
www.youtube.com/s/player/57fefa84/player_es6.vflset/en_US/remote.js	34.4 KiB
/s/youtubesans/v32/Qw38ZQNGEDjaO2m6tqIqX5E-AVS5_rSejo46_P...	31.5 KiB
www.google.com/js/th/PF32M1WFt3Opj6X4HHxBvSVo4hj3YoJbcs9XKKWIAD0.js	23.5 KiB
www.youtube.com/s/player/57fefa84/player_es6.vflset/en_US/offline.js	23.0 KiB

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

●Layout shift culprits

●Document request latency

●Optimize DOM size

●Font display

●Improve image delivery

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●User Timing marks and measures 33 user timings

●Avoid long main-thread tasks 6 long tasks found

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

●Network Requests

●Network Round Trip Times 50 ms

●Server Backend Latencies 60 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Avoid multiple page redirects

●Initial server response time was short Root document took 140 ms

●Avoid large layout shifts 5 layout shifts found

○INP breakdown

○LCP request discovery

○Avoid non-composited animations

Accessibility

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.

Failing Elements
About `ytd-guide-renderer#guide-renderer > div#footer > div#guide-links-primary > a`
Press `ytd-guide-renderer#guide-renderer > div#footer > div#guide-links-primary > a`
Copyright `ytd-guide-renderer#guide-renderer > div#footer > div#guide-links-primary > a`
Contact us `ytd-guide-renderer#guide-renderer > div#footer > div#guide-links-primary > a`
Creators `ytd-guide-renderer#guide-renderer > div#footer > div#guide-links-primary > a`
Developers `ytd-guide-renderer#guide-renderer > div#footer > div#guide-links-primary > a`
Terms `ytd-guide-renderer#guide-renderer > div#footer > div#guide-links-secondary > a`
Privacy `ytd-guide-renderer#guide-renderer > div#footer > div#guide-links-secondary > a`
How YouTube works `ytd-guide-renderer#guide-renderer > div#footer > div#guide-links-secondary > a`
Test new features `ytd-guide-renderer#guide-renderer > div#footer > div#guide-links-secondary > a`
NFL Sunday Ticket `ytd-guide-renderer#guide-renderer > div#footer > div#guide-links-secondary > a`

These items highlight common accessibility best practices.

○Interactive controls are keyboard focusable

○Interactive elements indicate their purpose and state

○The page has a logical tab order

○Visual order on the page follows DOM order

○User focus is not accidentally trapped in a region

○The user's focus is directed to new content added to the page

○HTML5 landmark elements are used to improve navigation

○Offscreen content is hidden from assistive technology

○Custom controls have associated labels

○Custom controls have ARIA roles

●`[aria-*]` attributes match their roles

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

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

●`[role]` values are valid

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

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

●Buttons have an accessible name

●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

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

●Elements use only permitted ARIA attributes

●Elements with the `role=text` attribute do not have focusable descendents.

●ARIA `tooltip` elements have accessible names

●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

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

●Heading elements appear in a sequentially-descending order

●Document has a main landmark.

●Deprecated ARIA roles were not used

●Identical links have the same purpose.

●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

○ARIA toggle fields have accessible names

○ARIA `treeitem` elements have accessible names

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

○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.

○Definition list items are wrapped in `<dl>` elements

○ARIA IDs are unique

○No form fields have multiple labels

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

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

○Image elements have `[alt]` attributes

○Input buttons have discernible text.

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

○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

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

○`<object>` elements have alternate text

○Select elements have associated label elements.

○Skip links are focusable.

○Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.

○`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.

○`[lang]` attributes have a valid value

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

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

○All heading elements contain content.

○Uses ARIA roles only on compatible elements

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

○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

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

Source	Description
/videoplayback?expire=5432621261&ei=7SIj5nqH_C3iKBkI2AULa...	`Failed to load resource: the server responded with a status of 403 ()`
/videoplayback?expire=5432621261&ei=7SIj5nqH_C3iKBkI2AULa...	`Failed to load resource: the server responded with a status of 403 ()`
/videoplayback?expire=5432621261&ei=7SIj5nqH_C3iKBkI2AULa...	`Failed to load resource: the server responded with a status of 403 ()`
/videoplayback?expire=5432621261&ei=7SIj5nqH_C3iKBkI2AULa...	`Failed to load resource: the server responded with a status of 403 ()`
/videoplayback?expire=5432621261&ei=7SIj5nqH_C3iKBkI2AULa...	`Failed to load resource: the server responded with a status of 403 ()`
/videoplayback?expire=5432621261&ei=7SIj5nqH_C3iKBkI2AULa...	`Failed to load resource: the server responded with a status of 403 ()`

URL	Map URL
www.youtube.com/s/player/57fefa84/player_es6.vflset/en_US/base.js
/s/_/ytmainappweb/_/js/k=ytmainappweb.kevlar_base.en_US.z...
www.youtube.com/
/s/desktop/0203efec/jsbin/webcomponents-sd.vflset/webcomp...	/s/desktop/0203efec/jsbin/webcomponents-sd.vflset/blaze-o...
/s/desktop/0203efec/jsbin/web-animations-next-lite.min.vf...	/s/desktop/0203efec/jsbin/web-animations-next-lite.min.vf...
/s/desktop/0203efec/jsbin/custom-elements-es5-adapter.vfl...	/s/desktop/0203efec/jsbin/custom-elements-es5-adapter.vfl...
www.google.com/js/th/PF32M1WFt3Opj6X4HHxBvSVo4hj3YoJbcs9XKKWIAD0.js

●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 issues in the `Issues` panel in Chrome Devtools

●Use a strong HSTS policy

●Ensure proper origin isolation with COOP

●Detected JavaScript libraries

○Redirects HTTP traffic to HTTPS

○Ensure CSP is effective against XSS attacks

○Mitigate clickjacking with XFO or CSP

○Mitigate DOM-based XSS with Trusted Types

SEO

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

Uncrawlable Link
div.ytp-title-expanded-overlay > div.ytp-title-expanded-heading > div.ytp-title-expanded-title > a `div.ytp-title-expanded-overlay > div.ytp-title-expanded-heading > div.ytp-title-expanded-title > a`
div.ytp-chrome-top > div.ytp-title > div.ytp-title-text > a.ytp-title-link `div.ytp-chrome-top > div.ytp-title > div.ytp-title-text > a.ytp-title-link`
div.ytp-overlays-container > div.ytp-overlay-top-left > div.ytp-paid-content-overlay > a.ytp-paid-content-overlay-link `div.ytp-overlays-container > div.ytp-overlay-top-left > div.ytp-paid-content-overlay > a.ytp-paid-content-overlay-link`
div#ytp-id-6 > div.ytp-playlist-menu-header > div.ytp-playlist-menu-title > a.ytp-playlist-menu-title-name `div#ytp-id-6 > div.ytp-playlist-menu-header > div.ytp-playlist-menu-title > a.ytp-playlist-menu-title-name`
div#movie_player > div#ytp-id-9 > div.ytp-share-panel-inner-content > a.ytp-share-panel-link `div#movie_player > div#ytp-id-9 > div.ytp-share-panel-inner-content > a.ytp-share-panel-link`

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 have descriptive text

●robots.txt is valid

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`

○Image elements have `[alt]` attributes

Browse & Analyze

Learn

Results for https://www.youtube.com

Site Health

Top Priorities (5)

Lighthouse Scores

Core Web Vitals

Detailed Report

Performance

Insights

Diagnostics

Accessibility

Contrast

Best practices

Best Practices

General

SEO

Lighthouse Scores

Core Web Vitals

Detailed Report

Performance

Insights

Diagnostics

Accessibility

Best practices

Best Practices

General

SEO

Crawling and Indexing

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