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Results for https://redux.js.org

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Brazil Brazil · Sao Paulo Completed: Apr 4, 2026 18:42 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

No Content-Security-Policy header found

Security › Content Security Policy
3

Cross-Origin-Embedder-Policy header is missing

Security › Security Headers
4

Cross-Origin-Opener-Policy header is missing

Security › Security Headers
5

External script from redux-docs-umami.up.railway.app lacks integrity attribute

Security › Subresource Integrity
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<a href="https://beavercheck.com/results/444ca29f-7a95-4aba-a6a6-0a7615522ddc"><img src="https://beavercheck.com/badge?url=https%3A%2F%2Fredux.js.org" alt="BeaverCheck Score"></a>
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Lighthouse Scores

Industry-standard audits powered by Google Lighthouse.

90
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
100
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
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.

1.05 s

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

2.13 s

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

366 ms

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

0.000

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

1.05 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.

3.06 s

Detailed Report

Audit breakdown by category with detailed findings.

90

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.

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
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.

URLTransfer SizeDuration
redux.js.org/assets/css/styles.9a914e26.css15.0 KiB301 ms

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.

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.

Estimated savings: 300 ms 49.4 KiB
URLTransfer SizeEst Savings
redux.js.org/assets/js/main.869dfa69.js139.7 KiB49.4 KiB

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

URL
Redux.dev - a new course by Mark Erikson + ui.dev - Learn more main > section.course-callout > a > img
redux.js.org/img/course-callout-mid.svg
Redux Logo div.navbar__items > a.navbar__brand > div.navbar__logo > img.themedComponent_mlkZ
redux.js.org/img/redux.svg
Redux Logo div.navbar-sidebar__brand > a.navbar__brand > div.navbar__logo > img.themedComponent_mlkZ
redux.js.org/img/redux.svg
Deployed by Netlify ul.footer__items > li.footer__item > a > img
www.netlify.com/img/global/badges/netlify-color-accent.svg

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

Time to Interactive 3.1 s
Use efficient cache lifetimes
Layout shift culprits
Document request latency
Optimize DOM size
Font display
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 324 KiB
JavaScript execution time 0.9 s
Minimizes main-thread work 1.4 s
Avoid long main-thread tasks 5 long tasks found
Page didn't prevent back/forward cache restoration
Network Requests
Network Round Trip Times 0 ms
Server Backend Latencies 220 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 150 ms
INP breakdown
LCP request discovery
User Timing marks and measures
Avoid non-composited animations
Avoid large layout shifts
100

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.

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
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.
ARIA attributes are used as specified for the element's role
`[aria-hidden="true"]` elements do not contain focusable descendents
Elements use only permitted ARIA attributes
Background and foreground colors have a sufficient contrast ratio
Document has a `<title>` element
`<html>` element has a `[lang]` attribute
`<html>` element has a valid value for its `[lang]` attribute
Links 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.
Deprecated ARIA roles were not used
`[accesskey]` values are unique
`button`, `link`, and `menuitem` elements have accessible names
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
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.
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.
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.
96

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

SourceDescription
Failed to load resource: the server responded with a status of 400 ()
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
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
Detected JavaScript libraries
Page has valid source maps
Redirects HTTP traffic to HTTPS
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`
Document has a valid `rel=canonical`
robots.txt is valid

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.
100
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
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.

288 ms

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

456 ms

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

18 ms

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

0.005

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

288 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.

624 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.

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
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.

URLTransfer SizeDuration
redux.js.org/assets/css/styles.9a914e26.css14.9 KiB82 ms

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 10.4 KiB
URLTransfer SizeEst Savings
redux.js.org/assets/css/styles.9a914e26.css14.8 KiB10.4 KiB

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

Estimated savings: 40 ms 50.4 KiB
URLTransfer SizeEst Savings
redux.js.org/assets/js/main.869dfa69.js139.7 KiB50.4 KiB

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

URL
Redux.dev - a new course by Mark Erikson + ui.dev - Learn more main > section.course-callout > a > img
redux.js.org/img/course-callout-mid.svg
Redux Logo div.navbar__items > a.navbar__brand > div.navbar__logo > img.themedComponent_mlkZ
redux.js.org/img/redux.svg
Deployed by Netlify ul.footer__items > li.footer__item > a > img
www.netlify.com/img/global/badges/netlify-color-accent.svg

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

Max Potential First Input Delay 90 ms
Use efficient cache lifetimes
Layout shift culprits
Document request latency
Optimize DOM size
Font display
Forced reflow
Improve image delivery
LCP breakdown
Modern HTTP
Optimize viewport for mobile
Time to Interactive 0.6 s
Minify CSS
Minify JavaScript
Avoids enormous network payloads Total size was 359 KiB
JavaScript execution time 0.2 s
Minimizes main-thread work 0.4 s
Avoid long main-thread tasks 1 long task found
Page didn't prevent back/forward cache restoration
Network Requests
Network Round Trip Times 0 ms
Server Backend Latencies 210 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 10 ms
Avoid large layout shifts 1 layout shift found
INP breakdown
LCP request discovery
User Timing marks and measures
Avoid non-composited animations
100

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.

Visible text labels that do not match the accessible name can result in a confusing experience for screen reader users. Learn more about accessible names.

Failing Elements
Search ⌘ K canary-media-query > button.desktop
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
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.
ARIA attributes are used as specified for the element's role
`[aria-hidden="true"]` elements do not contain focusable descendents
Elements use only permitted ARIA attributes
Background and foreground colors have a sufficient contrast ratio
Document has a `<title>` element
`<html>` element has a `[lang]` attribute
`<html>` element has a valid value for its `[lang]` attribute
Links 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.
Deprecated ARIA roles were not used
Identical links have the same purpose.
`[accesskey]` values are unique
`button`, `link`, and `menuitem` elements have accessible names
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
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.
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.
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.
96

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

SourceDescription
Failed to load resource: the server responded with a status of 400 ()
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
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
Detected JavaScript libraries
Page has valid source maps
Redirects HTTP traffic to HTTPS
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`
Document has a valid `rel=canonical`
robots.txt is valid

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