There were issues affecting this run of Lighthouse:
- Something went wrong with recording the trace over your page load. Please run Lighthouse again. (NO_FCP)
Values are estimated and may vary. The performance score is calculated directly from these metrics.See calculator.
Metrics
First Contentful Paint
Error!
Required traces gatherer did not run.
Speed Index
Error!
Required traces gatherer did not run.
Largest Contentful Paint
Error!
Required traces gatherer did not run.
Time to Interactive
Error!
Required traces gatherer did not run.
Total Blocking Time
Error!
Required traces gatherer did not run.
Cumulative Layout Shift
Error!
Required traces gatherer did not run.
Show audits relevant to:
Diagnostics
Eliminate render-blocking resources Error!Required TagsBlockingFirstPaint gatherer did not run.
Required TagsBlockingFirstPaint gatherer did not run.
Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. Learn more.FCPLCP
Properly size images Error!Required ImageElements gatherer did not run.
Required ImageElements gatherer did not run.
Serve images that are appropriately-sized to save cellular data and improve load time. Learn more.
Minify CSS Error!Required CSSUsage gatherer did not run.
Required CSSUsage gatherer did not run.
Minify JavaScript Error!Required ScriptElements gatherer did not run.
Required ScriptElements gatherer did not run.
Reduce unused CSS Error!Required CSSUsage gatherer did not run.
Required CSSUsage gatherer did not run.
Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn more.FCPLCP
Reduce unused JavaScript Error!Required JsUsage gatherer did not run.
Required JsUsage gatherer did not run.
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn more.LCP
Efficiently encode images Error!Required OptimizedImages gatherer did not run.
Required OptimizedImages gatherer did not run.
Optimized images load faster and consume less cellular data. Learn more.
Serve images in next-gen formats Error!Required OptimizedImages gatherer did not run.
Required OptimizedImages gatherer did not run.
Image formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. Learn more.
Enable text compression Error!Required ResponseCompression gatherer did not run.
Required ResponseCompression gatherer did not run.
Text-based resources should be served with compression (gzip, deflate or brotli) to minimize total network bytes. Learn more.FCPLCP
Preconnect to required origins Error!Required traces gatherer did not run.
Required traces gatherer did not run.
Consider adding `preconnect` or `dns-prefetch` resource hints to establish early connections to important third-party origins. Learn more.FCPLCP
Initial server response time was short Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
Keep the server response time for the main document short because all other requests depend on it. Learn more.FCPLCP
Avoid multiple page redirects Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
Preload key requests Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
Consider using `<link rel=preload>` to prioritize fetching resources that are currently requested later in page load. Learn more.FCPLCP
Use HTTP/2 Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
HTTP/2 offers many benefits over HTTP/1.1, including binary headers and multiplexing. Learn more.
Use video formats for animated content Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
Large GIFs are inefficient for delivering animated content. Consider using MPEG4/WebM videos for animations and PNG/WebP for static images instead of GIF to save network bytes. Learn moreLCP
Remove duplicate modules in JavaScript bundles Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity. TBT
Avoid serving legacy JavaScript to modern browsers Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
Polyfills and transforms enable legacy browsers to use new JavaScript features. However, many aren't necessary for modern browsers. For your bundled JavaScript, adopt a modern script deployment strategy using module/nomodule feature detection to reduce the amount of code shipped to modern browsers, while retaining support for legacy browsers. Learn MoreTBT
Preload Largest Contentful Paint image Error!Required traces gatherer did not run.
Required traces gatherer did not run.
Preload the image used by the LCP element in order to improve your LCP time. Learn more.LCP
Avoids enormous network payloads Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
Large network payloads cost users real money and are highly correlated with long load times. Learn more.LCP
Uses efficient cache policy on static assets Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
A long cache lifetime can speed up repeat visits to your page. Learn more.
Avoids an excessive DOM size Error!Required DOMStats gatherer did not run.
Required DOMStats gatherer did not run.
A large DOM will increase memory usage, cause longer style calculations, and produce costly layout reflows. Learn more.TBT
Avoid chaining critical requests Error!Required traces gatherer did not run.
Required traces gatherer did not run.
The Critical Request Chains below show you what resources are loaded with a high priority. Consider reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load. Learn more.FCPLCP
User Timing marks and measures Error!Required traces gatherer did not run.
Required traces gatherer did not run.
Consider instrumenting your app with the User Timing API to measure your app's real-world performance during key user experiences. Learn more.
JavaScript execution time Error!Required traces gatherer did not run.
Required traces gatherer did not run.
Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn more.TBT
Minimizes main-thread work Error!Required traces gatherer did not run.
Required traces gatherer did not run.
Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn moreTBT
All text remains visible during webfont loads Error!Required devtoolsLogs gatherer did not run. Warnings: - Lighthouse was unable to automatically check the font-display value for the following URL: https://secure-ds.serving-sys.com/resources/PROD/html5/105657/20190307/1074580285/43862346571980472/fonts/IBMPlexSans-Light-Latin1.woff.
- Lighthouse was unable to automatically check the font-display value for the following URL: https://secure-ds.serving-sys.com/resources/PROD/html5/105657/20190307/1074580285/43862346571980472/fonts/IBMPlexSans-Bold-Latin1.woff.
Required devtoolsLogs gatherer did not run.
- Lighthouse was unable to automatically check the font-display value for the following URL: https://secure-ds.serving-sys.com/resources/PROD/html5/105657/20190307/1074580285/43862346571980472/fonts/IBMPlexSans-Light-Latin1.woff.
- Lighthouse was unable to automatically check the font-display value for the following URL: https://secure-ds.serving-sys.com/resources/PROD/html5/105657/20190307/1074580285/43862346571980472/fonts/IBMPlexSans-Bold-Latin1.woff.
Leverage the font-display CSS feature to ensure text is user-visible while webfonts are loading. Learn more.FCPLCP
Keep request counts low and transfer sizes small Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
To set budgets for the quantity and size of page resources, add a budget.json file. Learn more.
Minimize third-party usage Error!Required traces gatherer did not run.
Required traces gatherer did not run.
Third-party code can significantly impact load performance. Limit the number of redundant third-party providers and try to load third-party code after your page has primarily finished loading. Learn more.TBT
Lazy load third-party resources with facades Error!Required traces gatherer did not run.
Required traces gatherer did not run.
Some third-party embeds can be lazy loaded. Consider replacing them with a facade until they are required. Learn more.TBT
Largest Contentful Paint element Error!Required traces gatherer did not run.
Required traces gatherer did not run.
This is the largest contentful element painted within the viewport. Learn MoreLCP
Largest Contentful Paint image was not lazily loaded Error!Required TraceElements gatherer did not run.
Required TraceElements gatherer did not run.
Above-the-fold images that are lazily loaded render later in the page lifecycle, which can delay the largest contentful paint. Learn more.
Avoid large layout shifts Error!Required traces gatherer did not run.
Required traces gatherer did not run.
These DOM elements contribute most to the CLS of the page.CLS
Uses passive listeners to improve scrolling performance Error!Required ConsoleMessages gatherer did not run.
Required ConsoleMessages gatherer did not run.
Consider marking your touch and wheel event listeners as `passive` to improve your page's scroll performance. Learn more.
Avoids document.write()
Error!Required ConsoleMessages gatherer did not run.
document.write()
Error!Required ConsoleMessages gatherer did not run.
For users on slow connections, external scripts dynamically injected via `document.write()` can delay page load by tens of seconds. Learn more.
Avoid long main-thread tasks Error!Required traces gatherer did not run.
Required traces gatherer did not run.
Lists the longest tasks on the main thread, useful for identifying worst contributors to input delay. Learn moreTBT
Avoid non-composited animations Error!Required TraceElements gatherer did not run.
Required TraceElements gatherer did not run.
Animations which are not composited can be janky and increase CLS. Learn moreCLS
Image elements have explicit width
and height
Error!Required ImageElements gatherer did not run.
width
and height
Error!Required ImageElements gatherer did not run.
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn moreCLS
Has a <meta name="viewport">
tag with width
or initial-scale
Error!Required MetaElements gatherer did not run.
<meta name="viewport">
tag with width
or initial-scale
Error!Required MetaElements gatherer did not run.
A `<meta name="viewport">` not only optimizes your app for mobile screen sizes, but also prevents a 300 millisecond delay to user input. Learn more.TBT
Passed audits (1) Show Hide
Passed audits (1)
Show Hide
Defer offscreen images Warnings: Invalid image sizing information: https://cdn.cnn.com/cnn/.e1mo/img/4.0/vr/vr_new_asset.png
Consider lazy-loading offscreen and hidden images after all critical resources have finished loading to lower time to interactive. Learn more.
These checks highlight opportunities to improve the accessibility of your web app. Only a subset of accessibility issues can be automatically detected so manual testing is also encouraged.
ARIA
[aria-*]
attributes match their roles Error!Required Accessibility gatherer did not run.
[aria-*]
attributes match their roles Error!Required Accessibility gatherer did not run.
Each ARIA `role` supports a specific subset of `aria-*` attributes. Mismatching these invalidates the `aria-*` attributes. Learn more.
[aria-hidden="true"]
is not present on the document <body>
Error!Required Accessibility gatherer did not run.
[aria-hidden="true"]
is not present on the document <body>
Error!Required Accessibility gatherer did not run.
Assistive technologies, like screen readers, work inconsistently when `aria-hidden="true"` is set on the document `<body>`. Learn more.
[role]
s have all required [aria-*]
attributes Error!Required Accessibility gatherer did not run.
[role]
s have all required [aria-*]
attributes Error!Required Accessibility gatherer did not run.
Some ARIA roles have required attributes that describe the state of the element to screen readers. Learn more.
Elements with an ARIA [role]
that require children to contain a specific [role]
have all required children. Error!Required Accessibility gatherer did not run.
[role]
that require children to contain a specific [role]
have all required children. Error!Required Accessibility gatherer did not run.
Some ARIA parent roles must contain specific child roles to perform their intended accessibility functions. Learn more.
[role]
s are contained by their required parent element Error!Required Accessibility gatherer did not run.
[role]
s are contained by their required parent element Error!Required Accessibility gatherer did not run.
Some ARIA child roles must be contained by specific parent roles to properly perform their intended accessibility functions. Learn more.
[role]
values are valid Error!Required Accessibility gatherer did not run.
[role]
values are valid Error!Required Accessibility gatherer did not run.
ARIA roles must have valid values in order to perform their intended accessibility functions. Learn more.
[aria-*]
attributes have valid values Error!Required Accessibility gatherer did not run.
[aria-*]
attributes have valid values Error!Required Accessibility gatherer did not run.
Assistive technologies, like screen readers, can't interpret ARIA attributes with invalid values. Learn more.
[aria-*]
attributes are valid and not misspelled Error!Required Accessibility gatherer did not run.
[aria-*]
attributes are valid and not misspelled Error!Required Accessibility gatherer did not run.
Assistive technologies, like screen readers, can't interpret ARIA attributes with invalid names. Learn more.
ARIA IDs are unique Error!Required Accessibility gatherer did not run.
Required Accessibility gatherer did not run.
The value of an ARIA ID must be unique to prevent other instances from being overlooked by assistive technologies. Learn more.
button
, link
, and menuitem
elements have accessible names Error!Required Accessibility gatherer did not run.
button
, link
, and menuitem
elements have accessible names Error!Required Accessibility gatherer did not run.
When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
[aria-hidden="true"]
elements do not contain focusable descendents Error!Required Accessibility gatherer did not run.
[aria-hidden="true"]
elements do not contain focusable descendents Error!Required Accessibility gatherer did not run.
Focusable descendents within an `[aria-hidden="true"]` element prevent those interactive elements from being available to users of assistive technologies like screen readers. Learn more.
ARIA input fields have accessible names Error!Required Accessibility gatherer did not run.
Required Accessibility gatherer did not run.
When an input field doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
ARIA meter
elements have accessible names Error!Required Accessibility gatherer did not run.
meter
elements have accessible names Error!Required Accessibility gatherer did not run.
When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
ARIA progressbar
elements have accessible names Error!Required Accessibility gatherer did not run.
progressbar
elements have accessible names Error!Required Accessibility gatherer did not run.
When a `progressbar` element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
ARIA toggle fields have accessible names Error!Required Accessibility gatherer did not run.
Required Accessibility gatherer did not run.
When a toggle field doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
ARIA tooltip
elements have accessible names Error!Required Accessibility gatherer did not run.
tooltip
elements have accessible names Error!Required Accessibility gatherer did not run.
When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
ARIA treeitem
elements have accessible names Error!Required Accessibility gatherer did not run.
treeitem
elements have accessible names Error!Required Accessibility gatherer did not run.
When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
Names and labels
Buttons have an accessible name Error!Required Accessibility gatherer did not run.
Required Accessibility gatherer did not run.
When a button doesn't have an accessible name, screen readers announce it as "button", making it unusable for users who rely on screen readers. Learn more.
Image elements have [alt]
attributes Error!Required Accessibility gatherer did not run.
[alt]
attributes Error!Required Accessibility gatherer did not run.
Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more.
<input type="image">
elements have [alt]
text Error!Required Accessibility gatherer did not run.
<input type="image">
elements have [alt]
text Error!Required Accessibility gatherer did not run.
When an image is being used as an `<input>` button, providing alternative text can help screen reader users understand the purpose of the button. Learn more.
Form elements have associated labels Error!Required Accessibility gatherer did not run.
Required Accessibility gatherer did not run.
Labels ensure that form controls are announced properly by assistive technologies, like screen readers. Learn more.
Document has a <title>
element Error!Required Accessibility gatherer did not run.
<title>
element Error!Required Accessibility gatherer did not run.
The title gives screen reader users an overview of the page, and search engine users rely on it heavily to determine if a page is relevant to their search. Learn more.
<frame>
or <iframe>
elements have a title Error!Required Accessibility gatherer did not run.
<frame>
or <iframe>
elements have a title Error!Required Accessibility gatherer did not run.
Screen reader users rely on frame titles to describe the contents of frames. Learn more.
Links have a discernible name Error!Required Accessibility gatherer did not run.
Required Accessibility gatherer did not run.
Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users. Learn more.
<object>
elements have [alt]
text Error!Required Accessibility gatherer did not run.
<object>
elements have [alt]
text Error!Required Accessibility gatherer did not run.
Screen readers cannot translate non-text content. Adding alt text to `<object>` elements helps screen readers convey meaning to users. Learn more.
No form fields have multiple labels Error!Required Accessibility gatherer did not run.
Required Accessibility gatherer did not run.
Form fields with multiple labels can be confusingly announced by assistive technologies like screen readers which use either the first, the last, or all of the labels. Learn more.
Best practices
The document does not use <meta http-equiv="refresh">
Error!Required Accessibility gatherer did not run.
<meta http-equiv="refresh">
Error!Required Accessibility gatherer did not run.
Users do not expect a page to refresh automatically, and doing so will move focus back to the top of the page. This may create a frustrating or confusing experience. Learn more.
[user-scalable="no"]
is not used in the <meta name="viewport">
element and the [maximum-scale]
attribute is not less than 5. Error!Required Accessibility gatherer did not run.
[user-scalable="no"]
is not used in the <meta name="viewport">
element and the [maximum-scale]
attribute is not less than 5. Error!Required Accessibility gatherer did not run.
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.
Audio and video
These are opportunities to provide alternative content for audio and video. This may improve the experience for users with hearing or vision impairments.Navigation
[accesskey]
values are unique Error!Required Accessibility gatherer did not run.
[accesskey]
values are unique Error!Required Accessibility gatherer did not run.
Access keys let users quickly focus a part of the page. For proper navigation, each access key must be unique. Learn more.
The page contains a heading, skip link, or landmark region Error!Required Accessibility gatherer did not run.
Required Accessibility gatherer did not run.
Adding ways to bypass repetitive content lets keyboard users navigate the page more efficiently. Learn more.
[id]
attributes on active, focusable elements are unique Error!Required Accessibility gatherer did not run.
[id]
attributes on active, focusable elements are unique Error!Required Accessibility gatherer did not run.
All focusable elements must have a unique `id` to ensure that they're visible to assistive technologies. Learn more.
No element has a [tabindex]
value greater than 0 Error!Required Accessibility gatherer did not run.
[tabindex]
value greater than 0 Error!Required Accessibility gatherer did not run.
A value greater than 0 implies an explicit navigation ordering. Although technically valid, this often creates frustrating experiences for users who rely on assistive technologies. Learn more.
Heading elements appear in a sequentially-descending order Error!Required Accessibility gatherer did not run.
Required Accessibility gatherer did not run.
Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. Learn more.
Contrast
Background and foreground colors have a sufficient contrast ratio Error!Required Accessibility gatherer did not run.
Required Accessibility gatherer did not run.
Low-contrast text is difficult or impossible for many users to read. Learn more.
Tables and lists
<dl>
's contain only properly-ordered <dt>
and <dd>
groups, <script>
, <template>
or <div>
elements. Error!Required Accessibility gatherer did not run.
<dl>
's contain only properly-ordered <dt>
and <dd>
groups, <script>
, <template>
or <div>
elements. Error!Required Accessibility gatherer did not run.
When definition lists are not properly marked up, screen readers may produce confusing or inaccurate output. Learn more.
Definition list items are wrapped in <dl>
elements Error!Required Accessibility gatherer did not run.
<dl>
elements Error!Required Accessibility gatherer did not run.
Definition list items (`<dt>` and `<dd>`) must be wrapped in a parent `<dl>` element to ensure that screen readers can properly announce them. Learn more.
Lists contain only <li>
elements and script supporting elements (<script>
and <template>
). Error!Required Accessibility gatherer did not run.
<li>
elements and script supporting elements (<script>
and <template>
). Error!Required Accessibility gatherer did not run.
Screen readers have a specific way of announcing lists. Ensuring proper list structure aids screen reader output. Learn more.
List items (<li>
) are contained within <ul>
or <ol>
parent elements Error!Required Accessibility gatherer did not run.
<li>
) are contained within <ul>
or <ol>
parent elements Error!Required Accessibility gatherer did not run.
Screen readers require list items (`<li>`) to be contained within a parent `<ul>` or `<ol>` to be announced properly. Learn more.
Cells in a <table>
element that use the [headers]
attribute refer to table cells within the same table. Error!Required Accessibility gatherer did not run.
<table>
element that use the [headers]
attribute refer to table cells within the same table. Error!Required Accessibility gatherer did not run.
Screen readers have features to make navigating tables easier. Ensuring `<td>` cells using the `[headers]` attribute only refer to other cells in the same table may improve the experience for screen reader users. Learn more.
<th>
elements and elements with [role="columnheader"/"rowheader"]
have data cells they describe. Error!Required Accessibility gatherer did not run.
<th>
elements and elements with [role="columnheader"/"rowheader"]
have data cells they describe. Error!Required Accessibility gatherer did not run.
Screen readers have features to make navigating tables easier. Ensuring table headers always refer to some set of cells may improve the experience for screen reader users. Learn more.
Internationalization and localization
<html>
element has a [lang]
attribute Error!Required Accessibility gatherer did not run.
<html>
element has a [lang]
attribute Error!Required Accessibility gatherer did not run.
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.
<html>
element has a valid value for its [lang]
attribute Error!Required Accessibility gatherer did not run.
<html>
element has a valid value for its [lang]
attribute Error!Required Accessibility gatherer did not run.
Specifying a valid BCP 47 language helps screen readers announce text properly. Learn more.
[lang]
attributes have a valid value Error!Required Accessibility gatherer did not run.
[lang]
attributes have a valid value Error!Required Accessibility gatherer did not run.
Specifying a valid BCP 47 language on elements helps ensure that text is pronounced correctly by a screen reader. Learn more.
Additional items to manually check (10) Show Hide
Additional items to manually check (10)
Show Hide
The page has a logical tab order
Tabbing through the page follows the visual layout. Users cannot focus elements that are offscreen. Learn more.
Interactive controls are keyboard focusable
Custom interactive controls are keyboard focusable and display a focus indicator. Learn more.
Interactive elements indicate their purpose and state
Interactive elements, such as links and buttons, should indicate their state and be distinguishable from non-interactive elements. Learn more.
The user's focus is directed to new content added to the page
If new content, such as a dialog, is added to the page, the user's focus is directed to it. Learn more.
User focus is not accidentally trapped in a region
A user can tab into and out of any control or region without accidentally trapping their focus. Learn more.
Custom controls have associated labels
Custom interactive controls have associated labels, provided by aria-label or aria-labelledby. Learn more.
Custom controls have ARIA roles
Custom interactive controls have appropriate ARIA roles. Learn more.
Visual order on the page follows DOM order
DOM order matches the visual order, improving navigation for assistive technology. Learn more.
Offscreen content is hidden from assistive technology
Offscreen content is hidden with display: none or aria-hidden=true. Learn more.
HTML5 landmark elements are used to improve navigation
Landmark elements (<main>, <nav>, etc.) are used to improve the keyboard navigation of the page for assistive technology. Learn more.
Trust and Safety
Uses HTTPS Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
All sites should be protected with HTTPS, even ones that don't handle sensitive data. This includes avoiding mixed content, where some resources are loaded over HTTP despite the initial request being served over HTTPS. HTTPS prevents intruders from tampering with or passively listening in on the communications between your app and your users, and is a prerequisite for HTTP/2 and many new web platform APIs. Learn more.
Avoids requesting the geolocation permission on page load Error!Required ConsoleMessages gatherer did not run.
Required ConsoleMessages gatherer did not run.
Users are mistrustful of or confused by sites that request their location without context. Consider tying the request to a user action instead. Learn more.
Avoids requesting the notification permission on page load Error!Required ConsoleMessages gatherer did not run.
Required ConsoleMessages gatherer did not run.
Users are mistrustful of or confused by sites that request to send notifications without context. Consider tying the request to user gestures instead. Learn more.
Ensure CSP is effective against XSS attacks Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
A strong Content Security Policy (CSP) significantly reduces the risk of cross-site scripting (XSS) attacks. Learn more
User Experience
Allows users to paste into password fields Error!Required PasswordInputsWithPreventedPaste gatherer did not run.
Required PasswordInputsWithPreventedPaste gatherer did not run.
Preventing password pasting undermines good security policy. Learn more.
Displays images with correct aspect ratio Error!Required ImageElements gatherer did not run.
Required ImageElements gatherer did not run.
Image display dimensions should match natural aspect ratio. Learn more.
Serves images with appropriate resolution Error!Required ImageElements gatherer did not run.
Required ImageElements gatherer did not run.
Image natural dimensions should be proportional to the display size and the pixel ratio to maximize image clarity. Learn more.
Fonts with font-display: optional
are preloaded Error!Required devtoolsLogs gatherer did not run.
font-display: optional
are preloaded Error!Required devtoolsLogs gatherer did not run.
Preload `optional` fonts so first-time visitors may use them. Learn more
Browser Compatibility
Page has the HTML doctype Error!Required Doctype gatherer did not run.
Required Doctype gatherer did not run.
Specifying a doctype prevents the browser from switching to quirks-mode. Learn more.
Properly defines charset Error!Required MainDocumentContent gatherer did not run.
Required MainDocumentContent gatherer did not run.
A character encoding declaration is required. It can be done with a `<meta>` tag in the first 1024 bytes of the HTML or in the Content-Type HTTP response header. Learn more.
General
Avoids unload
event listeners Error!Required GlobalListeners gatherer did not run.
unload
event listeners Error!Required GlobalListeners gatherer did not run.
The `unload` event does not fire reliably and listening for it can prevent browser optimizations like the Back-Forward Cache. Consider using the `pagehide` or `visibilitychange` events instead. Learn more
Avoids deprecated APIs Error!Required ConsoleMessages gatherer did not run.
Required ConsoleMessages gatherer did not run.
Deprecated APIs will eventually be removed from the browser. Learn more.
No browser errors logged to the console Error!Required ConsoleMessages gatherer did not run.
Required ConsoleMessages gatherer did not run.
Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more
No issues in the Issues
panel in Chrome Devtools Error!Required InspectorIssues gatherer did not run.
Issues
panel in Chrome Devtools Error!Required InspectorIssues gatherer did not run.
Issues logged to the `Issues` panel in Chrome Devtools indicate unresolved problems. They can come from network request failures, insufficient security controls, and other browser concerns. Open up the Issues panel in Chrome DevTools for more details on each issue.
Page has valid source maps Error!Required ScriptElements gatherer did not run.
Required ScriptElements gatherer did not run.
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.
Passed audits (1) Show Hide
Passed audits (1)
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Avoids front-end JavaScript libraries with known security vulnerabilities
Some third-party scripts may contain known security vulnerabilities that are easily identified and exploited by attackers. Learn more.
Not applicable (1) Show Hide
Not applicable (1)
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Detected JavaScript libraries
All front-end JavaScript libraries detected on the page. Learn more.
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.
Mobile Friendly
Has a <meta name="viewport">
tag with width
or initial-scale
Error!Required MetaElements gatherer did not run.
<meta name="viewport">
tag with width
or initial-scale
Error!Required MetaElements gatherer did not run.
A `<meta name="viewport">` not only optimizes your app for mobile screen sizes, but also prevents a 300 millisecond delay to user input. Learn more.TBT
Document uses legible font sizes Error!Required FontSize gatherer did not run.
Required FontSize gatherer did not run.
Font sizes less than 12px are too small to be legible and require mobile visitors to “pinch to zoom” in order to read. Strive to have >60% of page text ≥12px. Learn more.
Tap targets are sized appropriately Error!Required MetaElements gatherer did not run.
Required MetaElements gatherer did not run.
Interactive elements like buttons and links should be large enough (48x48px), and have enough space around them, to be easy enough to tap without overlapping onto other elements. Learn more.
Content Best Practices
Document has a <title>
element Error!Required Accessibility gatherer did not run.
<title>
element Error!Required Accessibility gatherer did not run.
The title gives screen reader users an overview of the page, and search engine users rely on it heavily to determine if a page is relevant to their search. Learn more.
Document has a meta description Error!Required MetaElements gatherer did not run.
Required MetaElements gatherer did not run.
Meta descriptions may be included in search results to concisely summarize page content. Learn more.
Links have descriptive text Error!Required AnchorElements gatherer did not run.
Required AnchorElements gatherer did not run.
Descriptive link text helps search engines understand your content. Learn more.
Image elements have [alt]
attributes Error!Required Accessibility gatherer did not run.
[alt]
attributes Error!Required Accessibility gatherer did not run.
Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more.
Document has a valid hreflang
Error!Required LinkElements gatherer did not run.
hreflang
Error!Required LinkElements gatherer did not run.
hreflang links tell search engines what version of a page they should list in search results for a given language or region. Learn more.
Document has a valid rel=canonical
Error!Required LinkElements gatherer did not run.
rel=canonical
Error!Required LinkElements gatherer did not run.
Canonical links suggest which URL to show in search results. Learn more.
Document avoids plugins Error!Required EmbeddedContent gatherer did not run.
Required EmbeddedContent gatherer did not run.
Search engines can't index plugin content, and many devices restrict plugins or don't support them. Learn more.
Crawling and Indexing
Page has successful HTTP status code Error!Required devtoolsLogs gatherer did not run.
Required devtoolsLogs gatherer did not run.
Pages with unsuccessful HTTP status codes may not be indexed properly. Learn more.
Links are crawlable Error!Required AnchorElements gatherer did not run.
Required AnchorElements gatherer did not run.
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 More
Page isn’t blocked from indexing Error!Required MetaElements gatherer did not run.
Required MetaElements gatherer did not run.
Search engines are unable to include your pages in search results if they don't have permission to crawl them. Learn more.
robots.txt is valid Error!Required RobotsTxt gatherer did not run.
Required RobotsTxt gatherer did not run.
If your robots.txt file is malformed, crawlers may not be able to understand how you want your website to be crawled or indexed. Learn more.
Additional items to manually check (1) Show Hide
Additional items to manually check (1)
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Structured data is valid
Run the Structured Data Testing Tool and the Structured Data Linter to validate structured data. Learn more.
These checks validate the aspects of a Progressive Web App. Learn more.
Installable
Web app manifest or service worker do not meet the installability requirements 1 reason
Service worker is the technology that enables your app to use many Progressive Web App features, such as offline, add to homescreen, and push notifications. With proper service worker and manifest implementations, browsers can proactively prompt users to add your app to their homescreen, which can lead to higher engagement. Learn more.
Failure reason |
---|
No manifest was fetched |
PWA Optimized
Registers a service worker that controls page and start_url
Error!Required ServiceWorker gatherer did not run.
start_url
Error!Required ServiceWorker gatherer did not run.
The service worker is the technology that enables your app to use many Progressive Web App features, such as offline, add to homescreen, and push notifications. Learn more.
Is not configured for a custom splash screenFailures: No manifest was fetched.
Failures: No manifest was fetched.
A themed splash screen ensures a high-quality experience when users launch your app from their homescreens. Learn more.
Sets a theme color for the address bar. Error!Required MetaElements gatherer did not run.
Required MetaElements gatherer did not run.
The browser address bar can be themed to match your site. Learn more.
Content is sized correctly for the viewport Error!Required ViewportDimensions gatherer did not run.
Required ViewportDimensions gatherer did not run.
If the width of your app's content doesn't match the width of the viewport, your app might not be optimized for mobile screens. Learn more.
Has a <meta name="viewport">
tag with width
or initial-scale
Error!Required MetaElements gatherer did not run.
<meta name="viewport">
tag with width
or initial-scale
Error!Required MetaElements gatherer did not run.
A `<meta name="viewport">` not only optimizes your app for mobile screen sizes, but also prevents a 300 millisecond delay to user input. Learn more.TBT
Provides a valid apple-touch-icon
Warnings: `apple-touch-icon-precomposed` is out of date; `apple-touch-icon` is preferred.
apple-touch-icon
For ideal appearance on iOS when users add a progressive web app to the home screen, define an `apple-touch-icon`. It must point to a non-transparent 192px (or 180px) square PNG. Learn More.
Manifest doesn't have a maskable iconNo manifest was fetched
No manifest was fetched
A maskable icon ensures that the image fills the entire shape without being letterboxed when installing the app on a device. Learn more.
Additional items to manually check (3) Show Hide
Additional items to manually check (3)
Show Hide
Site works cross-browser
To reach the most number of users, sites should work across every major browser. Learn more.
Page transitions don't feel like they block on the network
Transitions should feel snappy as you tap around, even on a slow network. This experience is key to a user's perception of performance. Learn more.
Each page has a URL
Ensure individual pages are deep linkable via URL and that URLs are unique for the purpose of shareability on social media. Learn more.