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EN 301 549 (Accessibility requirements for ICT products and services) is the European standard, published jointly by CEN, CENELEC and ETSI, that defines the accessibility requirements for information and communication technology products and services and how they are to be tested. Accessibility
What is EN 301 549?
EN 301 549 is the European standard, published jointly by CEN, CENELEC and ETSI, that defines the accessibility requirements for information and communication technology products and services and how they are to be tested.
For a company offering services to consumers in the EU, this is the standard referred to on the European side of a web accessibility audit. The standard is not only about websites; it also covers hardware, software, documents, real-time communication and product information. Its clauses begin with functional performance criteria, followed by generic requirements, two-way real-time communication, video, hardware, web, non-web documents, non-web software, information about products and services, and access to relay and emergency services. A test method is also defined for each requirement; the standard’s first version was prepared for use in public procurement.
The web clause (clause 9) rests directly on WCAG. The standard’s V4.1.0 draft dated November 2025 states this explicitly: conformance with WCAG 2.2 at level AA is equivalent to conformance with all of the web clauses and with the clause that carries over WCAG’s conformance requirements verbatim. In other words, meeting EN 301 549 on the web side means, in practice, meeting WCAG’s A and AA criteria together; the difference is explained in the A, AA and AAA guide.
- V3.2.1 (March 2021) — prepared as a voluntary route to conformance for the EU directive on the accessibility of public sector websites and mobile applications (2016/2102).
- V4.1.0 (draft, November 2025) — prepared at the Commission’s standardization request for the European Accessibility Act (Directive 2019/882); the web, document and software clauses were aligned with WCAG 2.2.
The standard’s legal effect depends on the Official Journal. According to the draft’s own foreword, once the standard’s reference is published in the Official Journal of the EU under the relevant directive, a product or service that conforms to the standard is presumed to conform to the corresponding requirements of that directive. The text of the European Accessibility Act does not name the standard; the link is made through this presumption. Which version has had its reference published under which directive changes over time; check the current status against the official list.
The practical meaning for a Turkish company: if you offer services online to consumers in the EU, the technical yardstick for your preparation will most likely be this standard’s web clause. Who falls within scope is covered in the guide to the European Accessibility Act. This site’s own baseline is WCAG 2.2 AA: a 2-pixel focus ring, touch targets of at least 44 pixels, and every release passes an automated audit and a suite of 1462 tests before going live.
If you want to know whether your site meets these criteria, the web accessibility audit measures every template against WCAG 2.2 point by point, fixes problems at the source and documents the result.
Accessibility
Entity An entity means a distinct thing that search and answer engines recognise — a person, an organisation, a place, a product or a concept. Answer engines
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Field data is the sum of performance measurements experienced by real users on real devices and real networks. Performance
Focus trap A focus trap is when keyboard focus enters a region and cannot leave it again, and WCAG prohibits it explicitly at level A. Accessibility
Font subset A font subset is a font file regenerated with only the characters that are needed. Multilingual
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GEO (Generative Engine Optimization) is the work of increasing the likelihood that a site is chosen as a source in the answers generated by AI systems. Answer engines
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hreflang is the markup that declares a page’s different language and region versions to search engines. Multilingual
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Index (search index) The index is the database in which a search engine keeps the pages it has decided to store out of those it crawled, and the only place it selects search results from; it is also called the search index. Being found on Google
IndexNow is an open protocol that tells search engines immediately that a page has changed. Answer engines
INP (Interaction to Next Paint) is the time from a user interaction until the page responds visually, and Google counts anything under 200 milliseconds as good. Performance
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JSON-LD (JavaScript Object Notation for Linked Data) is a structured data format that declares a page’s meaning in a machine-readable form without changing the page’s appearance at all. Answer engines
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Language tag (BCP 47) A language tag is the standard coding form that tells machines which language a text is in. Multilingual
LCP (Largest Contentful Paint) is the paint time of the largest content element in a page’s visible area, and Google counts anything under 2.5 seconds as good. Performance
Live region A live region is an area of a page whose changes a screen reader has to announce to the user. Accessibility
llms.txt is an optional file placed in a website’s root directory that summarises, in Markdown, what the site is about and where its most important pages are for language models. Answer engines
Locale A locale is the setting that defines a user’s language and region together and determines the formatting rules. Multilingual
Localisation (Localization) is adapting content to the culture, habits and search language of a target market; it is a wider undertaking than translation. Multilingual
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noindex is a directive asking that a page not be added to a search engine’s index, given either with the robots meta tag inside the page or with the server’s X-Robots-Tag response header. Being found on Google
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Redirect chain A redirect chain is when an address reaches its final address not in a single hop but by passing through more than one redirect; for example, if an old address is redirected first to an intermediate address and from there to the final address, there is a two-hop chain. Site migration
Reflow A reflow is the browser recomputing the positions and sizes of elements on a page after a change. Performance
Relative luminance is the value expressing a colour’s perceived lightness between 0 and 1, and it is the basis of the contrast ratio calculation. Accessibility
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Screen reader A screen reader is assistive technology that turns on-screen content into speech or braille output and lets the user navigate by keyboard. Accessibility
Search Console is a free service from Google for monitoring a site’s status in Google Search and for seeing and fixing its problems. Being found on Google
Semantic HTML means choosing each element for its meaning rather than its appearance — a heading element for a heading, a button element for a button, a list element for a list. Accessibility
Sitemap A sitemap is a file, usually written in XML, that lists the addresses of a site’s pages and, optionally, their last modification dates for search engines in a single file. Being found on Google
Soft 404 A soft 404 is a page that shows visitors “page not found” or empty content but returns a 200 (success) code from the server instead of an error code; Google treats these pages as error pages and does not index them. Site migration
Structured data is an additional layer that labels a page’s content with a standard vocabulary machines can understand. Answer engines
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Text expansion is the same content being of different lengths in different languages, and the layout having to flex accordingly. Multilingual
Translation memory A translation memory is a database that stores previously translated sentences and suggests them when the same or a similar sentence comes up again. Multilingual
TTFB (Time to First Byte) is the time between the browser sending a request and receiving the first byte from the server. Performance
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URL inventory A URL inventory is a single list that gathers every address of a site that search engines know — current pages, address variants and old addresses; in a site redesign or migration, the redirect map is derived from this list. Site migration
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WCAG (Web Content Accessibility Guidelines) is the international standard published by the W3C that defines the accessibility of web content through testable success criteria. Accessibility
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x-default is a special hreflang value declaring the default page to show when no language version matches the user’s language. Multilingual