Usability guidance

Policy and guidance that supports usable, user-friendly website design.

Usability indicators, guidance, and related standards
Indicators	Guidance	Standards
	21st Century Integrated Digital Experience Act (IDEA) Modernizes government websites and digital services.	Hypertext Transfer Protocol Secure (HTTPS) HTTP Strict Transport Security (HSTS) Page title Page description Viewport meta tag
	28 CFR Part 35 State and local government web accessibility requirements.	Page title Page description Viewport meta tag
	Automated Readability Index (ARI) Measures text reading difficulty levels.	Readability
	U.S. Federal Website Standards Improves accessibility, consistency and user experience.	Page title Page description
	Flesch-Kincaid (FK) Measure how hard text is to read.	Readability
	Google Search Central Resources to improve site search rankings.	Canonical hreflang Link text www resolution
	GSA Site Scanning Checks and tracks federal .gov websites.	Canonical Cumulative Layout Shift (CLS) Largest Contentful Paint (LCP) Hypertext Transfer Protocol Secure (HTTPS) HTTP Strict Transport Security (HSTS) Open Graph site name Open Graph type Open Graph title Open Graph description Open Graph URL Open Graph image Open Graph image alt Page title Page description Sitemap XML Viewport meta tag
	Open Graph Improves how social media content shows.	Open Graph site name Open Graph type Open Graph title Open Graph description Open Graph URL Open Graph image Open Graph image alt
	Plain Writing Act of 2010 Mandates government documents use simple language.	Readability
	sitemaps.org Website sitemap standards.	Sitemap XML
	Web Content Accessibility Guidelines (WCAG) Rules for making websites accessible.	[accesskey] values are unique [aria-] attributes match their roles Uses ARIA roles only on compatible elements button, link, and menuitem elements have accessible names ARIA attributes are used as specified for the element's role Deprecated ARIA roles were not used Elements with role="dialog" or role="alertdialog" have accessible names [aria-hidden="true"] is not present on the document <body> [aria-hidden="true"] elements do not contain focusable descendents ARIA input fields have accessible names ARIA meter elements have accessible names ARIA progressbar elements have accessible names Elements use only permitted ARIA attributes [role]s have all required [aria-] attributes Elements with an ARIA [role] that require children to contain a specific [role] have all required children [role]s are contained by their required parent element [role] values are valid Elements with the role=text attribute do not have focusable descendents ARIA toggle fields have accessible names ARIA tooltip elements have accessible names ARIA treeitem elements have accessible names [aria-] attributes have valid values [aria-] attributes are valid and not misspelled Buttons have an accessible name The page contains a heading, skip link, or landmark region Background and foreground colors have a sufficient contrast ratio <dl>'s contain only properly-ordered <dt> and <dd> groups, <script>, <template> or <div> elements Definition list items are wrapped in <dl> elements Document has a <title> element ARIA IDs are unique No form fields have multiple labels <frame> or <iframe> elements have a title Heading elements appear in a sequentially-descending order <html> element has a [lang] attribute <html> element has a valid value for its [lang] attribute <html> element has an [xml:lang] attribute with the same base language as the [lang] attribute Image elements have [alt] attributes Image elements do not have [alt] attributes that are redundant text 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"> [user-scalable="no"] is not used in the <meta name="viewport"> element and the [maximum-scale] attribute is not less than 5 <object> elements have alternate text Select elements have associated label elements Skip links are focusable No element has a [tabindex] value greater than 0 Tables have different content in the summary attribute and <caption> Touch targets have sufficient size and spacing 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"] All heading elements contain content Identical links have the same purpose Document has a main landmark 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 Character encoding Image aspect ratio Valid doctype
	Web Vitals / Core Web Vitals Google's speed, interaction, and stability metrics.	Cumulative Layout Shift (CLS) First Contentful Paint (FCP) Interaction to Next Paint (INP) Largest Contentful Paint (LCP) Time to First Byte (TTFB)