WCAG 1.2.6: Sign Language (Prerecorded)

What This Rule Means

WCAG 1.2.6 is a Level AAA success criterion under Guideline 1.2 (Time-based Media). It states: Sign language interpretation is provided for all prerecorded audio content in synchronized media. In practice, this means that any video with an audio track — such as a promotional film, recorded webinar, product demonstration, news segment, or e-learning module — must include an embedded or synchronized sign language interpretation if the site aims to meet AAA conformance.

The criterion applies specifically to synchronized media, which WCAG defines as audio or video content where the audio and video tracks are synchronized together and both are needed to understand the content. A simple audio-only podcast does not fall under this criterion; however, a recorded video lecture with a presenter, slides, and audio narration does. Pure video content with no meaningful audio track is also excluded.

A pass requires one of the following: a sign language interpreter is visibly present within the video frame throughout the audio content; a secondary video track (picture-in-picture) displays the interpreter synchronized with the main content; or a separate, accessible link to a version of the video that includes sign language interpretation is prominently provided adjacent to the media player. The sign language interpretation must cover all meaningful spoken words, including dialogue, narration, and significant audio cues where feasible.

A fail occurs when prerecorded synchronized media contains audio content and no sign language interpretation of any kind is available. It also fails if an interpreter is provided but is not synchronized with the audio — for example, a loosely associated video that does not correspond directly to the media in question. Providing only captions or a text transcript, without sign language, is insufficient for this criterion (those address different success criteria: 1.2.2 and 1.2.8).

WCAG does not mandate a specific sign language. Because sign languages are distinct natural languages that vary by country and region — Turkish Sign Language (Türk İşaret Dili, or TİD) for Turkish content, American Sign Language (ASL) for English content aimed at American Deaf communities, British Sign Language (BSL) for UK content, and so on — content authors must use the sign language appropriate to the primary audience of the content. Using an incorrect sign language for the target audience renders the interpretation inaccessible and constitutes a failure.

Why It Matters

For many members of the Deaf community, a spoken or written language such as Turkish or English is a second language. Their first, native language is a sign language — TİD, ASL, BSL, or another regional variant. This is a critical distinction that is frequently misunderstood by developers and content creators. Written captions are helpful, but for a fluent Deaf signer whose literacy in the written majority language may be limited, captions can present a significant comprehension barrier. Sign language interpretation renders the same information in a fully natural, first-language format.

According to the World Health Organization, over 430 million people worldwide have disabling hearing loss, and this number is projected to grow to over 700 million by 2050. In Turkey alone, the Ministry of Family and Social Services estimates there are approximately 1.5 million people with hearing disabilities. Of these, a large proportion use Turkish Sign Language as their primary means of communication. When videos on public or commercial websites are published without TİD interpretation, these users are effectively excluded from accessing that information.

Consider a concrete real-world scenario: a Turkish bank publishes a series of recorded video tutorials explaining how to use its mobile banking application. The videos include a presenter speaking Turkish and on-screen animations. The bank provides Turkish captions but no TİD interpretation. A Deaf customer whose strongest language is TİD struggles to follow the written captions at the speed they appear and cannot complete the tutorial. This customer is forced to call the bank's phone helpline — an inaccessible channel — or visit a branch in person, creating a significant practical barrier that a sign language video track would have eliminated entirely.

Beyond disability inclusion, providing sign language interpretation signals institutional respect for Deaf culture and can differentiate a brand positively. For organizations in sectors such as education, healthcare, and financial services, it builds trust with a historically underserved community. While sign language interpretation does not directly influence search engine ranking, the supplementary accessible video content and associated metadata can support discoverability and engagement metrics.

Related Axe-core Rules

WCAG 1.2.6 requires manual testing and is not covered by automated axe-core rules. There is no axe-core rule that can automatically verify the presence, accuracy, or synchronization of sign language interpretation in a video. Here is why automated tools fall short:

• Automated tools cannot analyze video content semantically. Detecting whether a sign language interpreter is visible and accurately interpreting the audio requires human judgment — specifically, a qualified Deaf reviewer or a certified sign language interpreter who can assess both the audio content and the signed interpretation simultaneously. No current static analysis or DOM inspection can accomplish this.
• Automated tools cannot verify synchronization. Even if a tool could detect a person's presence in a video frame, it cannot determine whether the hand movements constitute valid sign language, whether the pacing matches the spoken audio, or whether the interpreter's signing covers all meaningful spoken content including idioms, technical terms, and proper nouns.
• Media player markup does not reveal interpretation tracks. A <video> element may contain multiple <track> elements for captions and subtitles, but there is no standard HTML track kind for sign language interpretation. Interpretation is typically provided as a second video layer or a separate linked video file, neither of which is semantically distinguishable from any other video resource by automated scanning.
• Absence is not detectable from page structure alone. Axe-core inspects the DOM. It cannot determine from the DOM that a video containing audio lacks a sign language track — only that a video element exists. The absence of interpretation is a content gap, not a markup error.

Manual review by a qualified assessor — ideally a native signer of the relevant sign language — is the only reliable testing method for this criterion.

How to Test

1. Identify all synchronized media on the page. Load the page and locate every <video> element, embedded iframe (YouTube, Vimeo, or similar), or custom media player. Note which ones contain prerecorded audio as part of a synchronized audio-video presentation. Exclude purely decorative videos with no audio track and exclude live-streamed content (which is governed by criterion 1.2.4 and 1.2.9, not 1.2.6).
2. Run an automated axe DevTools or Lighthouse scan for context. While neither tool will flag a missing sign language track directly, the automated scan may surface related issues such as missing captions (1.2.2) or missing audio descriptions (1.2.5). This helps build a complete picture of media accessibility. In axe DevTools, look for any violations under the Perceivable category related to the media elements you identified.
3. Check for a sign language interpretation track or linked version. For each applicable video, examine whether: (a) an interpreter is visible in the video itself; (b) a picture-in-picture interpreter overlay is present; (c) a clearly labeled link near the media player points to a version of the video that includes TİD or the appropriate regional sign language interpretation. Check the page source for any <track> elements and review their kind attributes — though note that no standardized kind value for sign language currently exists in HTML.
4. Evaluate the quality of the interpretation with a qualified reviewer. If a sign language interpretation is provided, have a native signer of the relevant sign language (or a certified interpreter) watch the video and assess whether the interpretation: is synchronized with the audio; covers all spoken content including technical vocabulary, names, and important audio cues; uses the correct regional sign language for the target audience; and is recorded with sufficient visual clarity (good lighting, neutral background, appropriate frame size showing hands and face).
5. Screen reader check for player controls. Using NVDA with Firefox or JAWS with Chrome, navigate to the media player using the Tab key. Confirm that any toggle for an interpretation track or a link to the interpreted version is keyboard accessible and announced correctly by the screen reader. This is relevant for Deaf-Blind users who may rely on braille displays alongside captions.
6. Check on mobile. Using VoiceOver on iOS Safari or TalkBack on Android Chrome, verify that the sign language track or interpreted version is equally accessible on mobile devices, as a large proportion of users in Turkey access web content via smartphones.

How to Fix

Video with no interpretation provided — Incorrect

<!-- A prerecorded video with captions but no sign language interpretation -->
<video controls width='800'>
  <source src='product-demo.mp4' type='video/mp4'>
  <track kind='captions' src='captions-tr.vtt' srclang='tr' label='Türkçe Altyazı' default>
</video>

Video with no interpretation provided — Correct

<!-- The original video is supplemented with a clearly labeled link to a TİD-interpreted version.
     The link is placed immediately adjacent to the player so it is easy to discover. -->
<figure>
  <video controls width='800' aria-describedby='vid-desc'>
    <source src='product-demo.mp4' type='video/mp4'>
    <track kind='captions' src='captions-tr.vtt' srclang='tr' label='Türkçe Altyazı' default>
  </video>
  <figcaption id='vid-desc'>
    Ürün tanıtım videosu.
    <a href='product-demo-tid.mp4'>
      Türk İşaret Dili (TİD) ile yorumlanmış versiyonu izleyin
    </a>
  </figcaption>
</figure>

Picture-in-picture interpreter overlay — Incorrect

<!-- Interpreter video exists but is hidden by default with no accessible toggle -->
<div class='player-wrapper'>
  <video id='main-video' controls src='webinar.mp4'></video>
  <video id='interpreter' src='interpreter.mp4' style='display:none'></video>
</div>

Picture-in-picture interpreter overlay — Correct

<!-- Interpreter overlay is visible by default and can be toggled.
     The toggle button is keyboard accessible and has a descriptive aria-label. -->
<div class='player-wrapper'>
  <div class='video-container' style='position:relative'>
    <video id='main-video' controls src='webinar.mp4'
           aria-label='Web semineri videosu'></video>
    <video id='interpreter-overlay' src='interpreter-tid.mp4'
           autoplay muted
           aria-label='Türk İşaret Dili yorumlayıcısı'
           style='position:absolute; bottom:16px; right:16px; width:200px; border-radius:8px'>
    </video>
  </div>
  <button type='button'
          id='toggle-interpreter'
          aria-pressed='true'
          aria-controls='interpreter-overlay'>
    İşaret Dili Yorumlayıcısını Gizle / Göster
  </button>
</div>

Separate accessible version linked from a media listing — Incorrect

<!-- Accessible version link uses vague text and is placed far from the video -->
<video controls src='lecture.mp4'></video>
<p>İçerik için <a href='lecture-accessible.mp4'>buraya tıklayın</a>.</p>

Separate accessible version linked from a media listing — Correct

<!-- Link text is descriptive; the relationship between the video and the interpreted
     version is clear; both links are in the same container as the video element. -->
<section aria-labelledby='lecture-title'>
  <h2 id='lecture-title'>Ders 3: Erişilebilirlik Temelleri</h2>
  <video controls src='lecture.mp4'
         aria-describedby='lecture-links'>
    <track kind='captions' src='lecture-tr.vtt' srclang='tr'
           label='Türkçe Altyazı' default>
  </video>
  <p id='lecture-links'>
    Bu videonun
    <a href='lecture-tid.mp4'>
      Türk İşaret Dili (TİD) ile yorumlanmış versiyonunu izleyin
    </a>.
  </p>
</section>

Common Mistakes

• Assuming captions are sufficient for WCAG 1.2.6. Captions satisfy criterion 1.2.2, not 1.2.6. Many Deaf users whose native language is a sign language have limited literacy in the written form of the spoken language. Providing only captions does not meet this criterion.
• Using the wrong sign language for the target audience. Publishing an ASL-interpreted video for Turkish Deaf users is not a valid solution. TİD (Türk İşaret Dili) is a distinct language from ASL, BSL, or DGS and must be used for Turkish-language content targeting Turkish audiences.
• Providing a sign language video that is not synchronized with the audio. Posting a loosely related TİD summary video rather than a synchronized, sentence-by-sentence interpretation of the original audio does not meet the requirement. The interpretation must match the timing and content of the spoken audio.
• Hiding the interpreter behind a non-accessible toggle. If the sign language track can be shown or hidden, the toggle control must be keyboard focusable, have a descriptive label, and communicate its current state via aria-pressed or equivalent. A visually styled but non-focusable <div> acting as a button will fail both this criterion and WCAG 4.1.2.
• Recording the interpreter with poor visual quality. An interpreter filmed in low light, against a cluttered background, with the hands cropped out of frame, or at a very small display size renders the sign language inaccessible regardless of technical presence. The recording must clearly show the interpreter's face, shoulders, and both hands.
• Linking to an interpreted version with vague anchor text such as 'click here' or 'accessible version'. The link must clearly indicate what the destination is — for example, 'Watch the TİD (Turkish Sign Language) interpreted version of this video' — so that screen reader users navigating by links can understand the purpose without surrounding context.
• Applying the criterion only to the homepage or featured videos while neglecting secondary content. WCAG 1.2.6 applies to all prerecorded synchronized media on the site, including FAQ videos, support tutorials, promotional clips in blog posts, and embedded third-party content if it is provided as part of the page's content.
• Not updating the sign language interpretation when the source video is updated. If the original video is re-recorded, dubbed, or re-edited, the sign language interpretation track becomes out of sync. Workflows must include a step to update or re-record the interpretation whenever the source media changes.
• Treating sign language interpretation as optional for short videos. WCAG 1.2.6 does not provide a length exemption. A thirty-second product video with spoken narration requires interpretation just as much as a two-hour recorded conference session.
• Placing the interpreted version link far from the media player. If the link to the TİD version is buried in a footer, a separate accessibility page, or a collapsed disclosure widget that is not immediately associated with the video, many users will never find it. The link must be immediately adjacent to the media player, ideally within the same <figure> or landmark region.

Relation to Turkey's Accessibility Regulations

Turkey's primary accessibility mandate for digital services is established by Presidential Circular 2025/10, published in the Official Gazette No. 32933 on June 21, 2025. This circular requires covered entities to meet a minimum conformance level of WCAG 2.2 Level AA for their digital platforms, including websites and mobile applications. Because WCAG 1.2.6 is a Level AAA criterion, it is not a legal baseline requirement under the circular — but its implications for covered organizations are significant and worth understanding.

The entities explicitly covered by Presidential Circular 2025/10 include: public institutions and government agencies at all levels; banks and financial institutions; e-commerce platforms; hospitals and private healthcare providers; telecommunications operators with 200,000 or more subscribers; travel agencies; private transportation companies; and private schools authorized by the Ministry of National Education (MoNE). All of these sectors regularly produce and publish video content — onboarding videos, service announcements, educational materials, health information campaigns — that falls squarely within the scope of WCAG 1.2.6.

Although AAA compliance is not mandatory, organizations in these sectors should consider implementing sign language interpretation proactively for several reasons. First, Turkey's Disability Law No. 5378 and associated regulations under the Ministry of Family and Social Services affirm the rights of Deaf citizens to access information in their native language, Turkish Sign Language. Second, as accessibility enforcement matures following the 2025 circular, AAA-level provisions may be incorporated into sector-specific secondary legislation — particularly for public institutions, healthcare providers, and educational organizations. Third, the Turkish Deaf community has been vocal through organizations such as the Turkish Federation of the Deaf (Türkiye İşitme Engelliler Spor Federasyonu and advocacy groups) about the inadequacy of captions-only approaches for video content.

For organizations subject to the circular that wish to demonstrate best-in-class accessibility — or that serve large Deaf user populations, such as hospitals, schools, and banks — implementing WCAG 1.2.6 by providing TİD interpretation for key video content is a concrete, high-impact step. It signals genuine commitment to inclusion beyond the legal minimum and positions the organization favorably as accessibility auditing and public reporting become more prevalent under the circular's enforcement framework.