Skip to content
https://belastingdienst.nl

Lighthouse Desktop

· 0 checks — Desktop Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.
SCORE
0
GRADE
FIX
0
REVIEW
0
PASS
0
INFO
0

Detailed Report

Audit breakdown by category with detailed findings.

67

Performance

Insights

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

RequestCache TTLTransfer Size
/wps/wcm/connect/nl/home/resources/2/5/2548bba2-44ba-4c33...0.0 ms1.9 MiB
download.belastingdienst.nl/assets/bold/bldc-icons-rhs/1.0.0/dist/js/icons.js0.0 ms1.3 MiB
www.belastingdienst.nl/bld-assets/bld/belastingdienst.css0.0 ms297.7 KiB
/wps/wcm/connect/nl/home/resources/b/a/ba507c06-467f-4421...0.0 ms209.0 KiB
/adobe/db1f754ddf26/345c851e2a0e/launch-da94bc0c02f3.min.js3600.0 s227.3 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-validat...0.0 ms124.6 KiB
www.belastingdienst.nl/bld-assets/bld/webcomponents/bld-webcomponents.js0.0 ms118.2 KiB
/assets/fonts/rhsiconfont/rhsiconfont.woff2?e5c4eddf5a76f...0.0 ms104.6 KiB
/assets/bold/bldc-icons-belastingdienst/1.0.0/dist/js/ico...0.0 ms102.6 KiB
www.belastingdienst.nl/bld-assets/bld/belastingdienst.js0.0 ms94.0 KiB
www.belastingdienst.nl/bld-assets/jquery/ui/jquery-ui.1.13.2.custom.min.js0.0 ms91.4 KiB
www.belastingdienst.nl/bld-assets/jquery/jquery-3.6.0.min.js0.0 ms89.3 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/index-36dcd2...0.0 ms88.3 KiB
/assets/bold/rofonts/1.0.2/fonts/ROsanswebtextitalic.woff0.0 ms84.1 KiB
/assets/bold/rofonts/1.0.2/fonts/ROsanswebtextregular.woff0.0 ms76.7 KiB
/assets/bold/rofonts/1.0.2/fonts/ROsanswebtextbold.woff0.0 ms69.8 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-sanitiz...0.0 ms65.7 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-transla...0.0 ms63.1 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-icon.se...0.0 ms63.0 KiB
www.belastingdienst.nl/bld-assets/bootstrap/bootstrap.min.js0.0 ms62.8 KiB
www.belastingdienst.nl/bld-assets/bld/bld-metrix/bld-metrix.js0.0 ms45.4 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-compone...0.0 ms41.1 KiB
www.belastingdienst.nl/bld-assets/packery/packery.pkgd.min.js0.0 ms38.1 KiB
/adobe/db1f754ddf26/345c851e2a0e/0a4907de70b6/hostedLibFi...3600.0 s35.7 KiB
/script/4329/webReader/webReader.js?pids=wr&notools=1&ena...0.0 ms28.1 KiB
www.belastingdienst.nl/common_ext/js/surveys/bld_efm_default.js0.0 ms26.5 KiB
www.belastingdienst.nl/bld-assets/bootstrap/popper.min.js0.0 ms22.6 KiB
www.belastingdienst.nl/bld-assets/bld/rhslogos/bld_logo.svg0.0 ms19.2 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/Observable-e...0.0 ms16.1 KiB
/script/4329/webReader/r/r2889/ReadSpeaker.Styles-Button....86400.0 s39.9 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/nl-a1e9a3ae.js0.0 ms14.0 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-menu.se...0.0 ms11.7 KiB
www.belastingdienst.nl/bld-assets/smartbanner/smartbanner.js0.0 ms11.1 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/css-theme-co...0.0 ms10.5 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-icon.en...0.0 ms9.8 KiB
/assets/bold/bldc-themes/2.0.0/dist/css/basecolors.css0.0 ms8.3 KiB
/assets/bold/bldc-themes/2.0.0/dist/css/belastingdienst-l...0.0 ms8.1 KiB
www.belastingdienst.nl/bld-assets/bld/bld-scripts-loader/bld-scripts-loader.js0.0 ms8.1 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/BehaviorSubj...0.0 ms7.1 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/package-70e5...0.0 ms6.9 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/date.const-3...0.0 ms6.7 KiB
www.belastingdienst.nl/bld-assets/bold/bold-service-loader-4.12.2.js0.0 ms6.4 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/style.helper...0.0 ms5.8 KiB
www.belastingdienst.nl/bld-assets/smartbanner/smartbanner.css0.0 ms4.2 KiB
download.belastingdienst.nl/assets/bold/bldc-components/4.12.2/dist/esm/index.js0.0 ms3.8 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-console...0.0 ms3.7 KiB
/adobe/db1f754ddf26/345c851e2a0e/0a4907de70b6/RC7164da07b...3600.0 s4.5 KiB
download.belastingdienst.nl/assets/css/fonts.css0.0 ms3.6 KiB
www.belastingdienst.nl/common_ext/js/bld_next.js0.0 ms3.4 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/keymap-42ed8...0.0 ms3.0 KiB
try.abtasty.com/e7e9d856425677bf0f1ca47515bfcc27.js30.0 s2.9 KiB
/adobe/db1f754ddf26/345c851e2a0e/0a4907de70b6/hostedLibFi...3600.0 s3.6 KiB
www.belastingdienst.nl/bld-assets/bld/bld-abtasty/bld-abtasty.js0.0 ms2.8 KiB
download.belastingdienst.nl/assets/bold/rofonts/1.0.2/css/rofonts.css0.0 ms2.6 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-user.se...0.0 ms2.5 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/_commonjsHel...0.0 ms2.5 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/unique-id-d2...0.0 ms2.4 KiB
/assets/bold/bldc-components/4.12.2/dist/esm/app-globals-...0.0 ms2.1 KiB

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:source label:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]
items: [map[reflowTime:31.352 source:map[type:text value:[unattributed]]] map[reflowTime:6.319 source:map[column:82 line:15 type:source-location url:https://download.belastingdienst.nl/assets/bold/bldc-components/4.12.2/dist/esm/bldc-icon.entry.js urlProvider:network]]]

Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLResource SizeEst Savings
Belastingdienst Waarmee kunnen we u helpen? body.bld-dv > div#bld-wrapper > main#mainContentSkip > div#home
/wps/wcm/connect/nl/home/resources/2/5/2548bba2-44ba-4c33...1.9 MiB1.7 MiB
Lees voor Grote plannen? Of verandert er iets? Wij helpen u op weg met tips, h… body.bld-dv > div#bld-wrapper > main#mainContentSkip > section#campagne-verandering
/wps/wcm/connect/nl/home/resources/b/a/ba507c06-467f-4421...207.2 KiB66.6 KiB

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:label label:Subpart valueType:text] map[key:duration label:Duration valueType:ms]]
items: [map[duration:380.885 label:Time to first byte subpart:timeToFirstByte] map[duration:1511.826 label:Resource load delay subpart:resourceLoadDelay] map[duration:1147.761 label:Resource load duration subpart:resourceLoadDuration] map[duration:36.031 label:Element render delay subpart:elementRenderDelay]]
lhId: page-0-DIV
nodeLabel: Belastingdienst Waarmee kunnen we u helpen?
path: 1,HTML,1,BODY,0,DIV,1,MAIN,0,DIV
selector: body.bld-dv > div#bld-wrapper > main#mainContentSkip > div#home
snippet: <div data-bld-bg-image="/wps/wcm/connect/nl/home/resources/2/5/2548bba2-44ba-4c33-86f1-55b1a298126…" id="home" class="bld-bg-image bld-bg-image-center" style="background-image: url(&quot;/wps/wcm/connect/nl/home/resources/2/5/2548bba2-44b…&quot;);">

Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading

Why this matters

Performance issues directly impact user engagement and conversion rates.

lhId: page-0-DIV
nodeLabel: Belastingdienst Waarmee kunnen we u helpen?
path: 1,HTML,1,BODY,0,DIV,1,MAIN,0,DIV
selector: body.bld-dv > div#bld-wrapper > main#mainContentSkip > div#home
snippet: <div data-bld-bg-image="/wps/wcm/connect/nl/home/resources/2/5/2548bba2-44ba-4c33-86f1-55b1a298126…" id="home" class="bld-bg-image bld-bg-image-center" style="background-image: url(&quot;/wps/wcm/connect/nl/home/resources/2/5/2548bba2-44b…&quot;);">

HTTP/2 and HTTP/3 offer many benefits over HTTP/1.1, such as multiplexing. Learn more about using modern HTTP.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLProtocol
www.belastingdienst.nl/wps/wcm/connect/nl/home/homehttp/1.1
www.belastingdienst.nl/bld-assets/smartbanner/smartbanner.csshttp/1.1
www.belastingdienst.nl/bld-assets/smartbanner/smartbanner.jshttp/1.1
/assets/bold/bldc-themes/2.0.0/dist/css/basecolors.csshttp/1.1
/assets/bold/bldc-themes/2.0.0/dist/css/belastingdienst-l...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-compone...http/1.1
www.belastingdienst.nl/bld-assets/bold/bold-service-loader-4.12.2.jshttp/1.1
www.belastingdienst.nl/bld-assets/bld/bld-scripts-loader/bld-scripts-loader.jshttp/1.1
download.belastingdienst.nl/assets/bold/rofonts/1.0.2/css/rofonts.csshttp/1.1
download.belastingdienst.nl/assets/css/fonts.csshttp/1.1
www.belastingdienst.nl/bld-assets/bld/belastingdienst.csshttp/1.1
www.belastingdienst.nl/bld-assets/bld/rhslogos/bld_logo.svghttp/1.1
www.belastingdienst.nl/bld-assets/jquery/jquery-3.6.0.min.jshttp/1.1
www.belastingdienst.nl/bld-assets/jquery/ui/jquery-ui.1.13.2.custom.min.jshttp/1.1
www.belastingdienst.nl/bld-assets/bootstrap/popper.min.jshttp/1.1
www.belastingdienst.nl/bld-assets/bootstrap/bootstrap.min.jshttp/1.1
www.belastingdienst.nl/bld-assets/bld/webcomponents/bld-webcomponents.jshttp/1.1
www.belastingdienst.nl/bld-assets/bld/belastingdienst.jshttp/1.1
www.belastingdienst.nl/common_ext/js/bld_next.jshttp/1.1
www.belastingdienst.nl/common_ext/js/surveys/bld_efm_default.jshttp/1.1
www.belastingdienst.nl/bld-assets/packery/packery.pkgd.min.jshttp/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/index-36dcd2...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/app-globals-...http/1.1
/assets/bold/bldc-icons-belastingdienst/1.0.0/dist/js/ico...http/1.1
download.belastingdienst.nl/assets/bold/bldc-icons-rhs/1.0.0/dist/js/icons.jshttp/1.1
download.belastingdienst.nl/assets/bold/bldc-components/4.12.2/dist/esm/index.jshttp/1.1
/assets/bold/rofonts/1.0.2/fonts/ROsanswebtextbold.woffhttp/1.1
/assets/bold/rofonts/1.0.2/fonts/ROsanswebtextregular.woffhttp/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-transla...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-menu.se...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-user.se...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-validat...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-icon.se...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-console...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/package-70e5...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/nl-a1e9a3ae.jshttp/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/_commonjsHel...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/BehaviorSubj...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/Observable-e...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/keymap-42ed8...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/date.const-3...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-sanitiz...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/bldc-icon.en...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/css-theme-co...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/style.helper...http/1.1
/assets/bold/bldc-components/4.12.2/dist/esm/unique-id-d2...http/1.1
www.belastingdienst.nl/bld-assets/bld/bld-abtasty/bld-abtasty.jshttp/1.1
www.belastingdienst.nl/bld-assets/bld/bld-metrix/bld-metrix.jshttp/1.1
/wps/wcm/connect/bldcontentnl/berichten/berichten_uitgebr...http/1.1
www.belastingdienst.nl/wps/wcm/connect/nl/layouts/megamenu/megamenu_nl.jsonhttp/1.1
/assets/bold/rofonts/1.0.2/fonts/ROsanswebtextitalic.woffhttp/1.1
/assets/fonts/rhsiconfont/rhsiconfont.woff2?e5c4eddf5a76f...http/1.1
www.belastingdienst.nl/wps/wcm/connect/cci-content/zoeken/nl/zoeken.jsonhttp/1.1
/wps/wcm/connect/nl/home/resources/2/5/2548bba2-44ba-4c33...http/1.1
/wps/wcm/connect/nl/home/resources/b/a/ba507c06-467f-4421...http/1.1
www.belastingdienst.nl/mbd/splunkstatus.jsonhttp/1.1
www.belastingdienst.nl/bld-assets/bld/images/favicon.icohttp/1.1

Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.

Why this matters

Performance issues directly impact user engagement and conversion rates.

description: [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints help the browser establish a connection earlier in the page load, saving time when the first request for that origin is made. The following are the origins that the page preconnected to.
title: Preconnected origins
value: no origins were preconnected
description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.
title: Preconnect candidates

Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

TTI

Diagnostics

Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 240 ms 277.9 KiB

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL
Logo Belastingdienst | Ministerie van Financiën, link naar homepage van Belasti… div.row > div.col-12 > a > img#bld-img-logo
www.belastingdienst.nl/bld-assets/bld/rhslogos/bld_logo.svg

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

●Layout shift culprits
●Optimize DOM size
●Optimize viewport for mobile
●Max Potential First Input Delay 30 ms
●Minify CSS
●JavaScript execution time 0.4 s
●Minimizes main-thread work 1.1 s
●Avoid long main-thread tasks 1 long task found
●Avoid non-composited animations 5 animated elements found
●Page didn't prevent back/forward cache restoration
●Network Requests
●Network Round Trip Times 40 ms
●Server Backend Latencies 20 ms
●Tasks
●Diagnostics
●Metrics
●Screenshot Thumbnails
●Final Screenshot
●Script Treemap Data
●Resources Summary
●Initial server response time was short Root document took 40 ms
●Avoid large layout shifts 15 layout shifts found
○INP breakdown
○User Timing marks and measures
97

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.

Navigation

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 about the `tabindex` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Ga naar hoofdinhoud div.container > ul > li > a#skiplink-mainContentSkip
Ga direct naar hoofdnavigatie div.container > ul > li > a#skiplink-navContentSkip
Ga direct naar footer div.container > ul > li > a#skiplink-footer
Logo Belastingdienst | Ministerie van Financiën, link naar homepage van Belasti… div.container > div.row > div.col-12 > a
Home div.container > ul#navContentSkip > li.nav-item > a.nav-link
Menu div.container > ul#navContentSkip > li.nav-item > a#bld-megamenu
div > form#search-header > div.input-group > input#bldSearchInput div > form#search-header > div.input-group > input#bldSearchInput
zoek form#search-header > div.input-group > div.input-group-append > button.btn
Inloggen div.container > ul#navContentSkip > li.nav-item > a#bld-loginmenu

These are opportunities to improve keyboard navigation in your application.

○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
●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.
●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.
●`[lang]` attributes have a valid value
●Heading elements appear in a sequentially-descending order
●`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.
●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
○`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
○Input buttons have discernible text.
○`<input type="image">` elements have `[alt]` text
○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.
○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.
○`<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.
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.

Why this matters

Performance issues directly impact user engagement and conversion rates.

●Uses HTTPS
●Avoids deprecated APIs
●Avoids third-party cookies
●Allows users to paste into input fields
●Avoids requesting the geolocation permission on page load
●Avoids requesting the notification permission on page load
●Displays images with correct aspect ratio
●Serves images with appropriate resolution
●Page has the HTML doctype
●Properly defines charset
●No browser errors logged to the console
●No issues in the `Issues` panel in Chrome Devtools
●Ensure CSP is effective against XSS attacks
●Use a strong HSTS policy
●Ensure proper origin isolation with COOP
●Mitigate DOM-based XSS with Trusted Types
●Detected JavaScript libraries
○Redirects HTTP traffic to HTTPS
○Mitigate clickjacking with XFO or CSP
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`

Send Feedback