508 Compliance for Video: Requirements, WCAG Criteria, and a Checklist

508 compliance means that information and communication technology (ICT) conforms to the Revised Section 508 Standards, the federal accessibility rules covering technology a federal agency develops, procures, maintains, or uses. For video specifically, a 508 compliant file satisfies the WCAG success criteria for synchronized media: synchronized captions, audio description for visual information the narration does not already convey, a text transcript, readable contrast, no content that flashes more than three times in one second, and a player operable entirely from a keyboard. The standards reach vendors too, because an agency cannot lawfully buy content that fails them.

The rest of this guide covers where the requirement comes from, which criteria apply to prerecorded versus live media, what a VPAT is, and a checklist to run before you publish.

What Section 508 Actually Requires

Section 508 amends the Rehabilitation Act of 1973 and is codified at 29 U.S.C. 794d. It obligates federal agencies to make their electronic and information technology accessible to people with disabilities, both employees and the public. The statute itself says nothing about captions or contrast ratios. That detail lives in the standards the U.S. Access Board writes, summarized on Section508.gov's laws and policies page.

The version that matters came out of the 2017 Refresh, issued by the Access Board on January 18, 2017 with a compliance date one year later. The key change for content producers is provision E205.4 of the Revised 508 Standards: electronic content must conform to the Level A and Level AA Success Criteria and Conformance Requirements in WCAG 2.0, incorporated by reference.

So the legal floor is WCAG 2.0 Level AA. In practice, build to Level AA of WCAG 2.1, which is backward compatible and satisfies the newer rules below at the same time.

Who Section 508 Binds, and Who Gets Pulled In Anyway

Section 508 binds federal agencies directly and vendors indirectly, because agency solicitations pass the requirement through to contract deliverables. If you sell training video, an LMS, or a course library to a federal buyer, your content is in scope. Three other forces pull private and education buyers into the same requirements:

• ADA Title II. The Department of Justice web and mobile app rule published April 24, 2024 sets WCAG 2.1 Level AA as the technical standard for state and local government web content, covering public universities, community colleges, and K-12 districts. A later interim final rule moved the compliance date to April 26, 2027 for entities serving 50,000 or more people, and April 26, 2028 for smaller and special district governments.
• State procurement law. Many states have adopted the federal standards, or close equivalents, for agency and public university purchasing.
• Section 504 and ADA Title III. Recipients of federal funding and places of public accommodation face obligations that inaccessible training video can violate even where Section 508 does not apply.

So "is this 508 compliant" has become the shorthand procurement question for accessible video, whether or not the statute is the operative law.

Which WCAG Success Criteria Apply to Video

Every criterion below is Level A or Level AA, so all are in scope. Level AAA criteria such as 1.2.6 Sign Language and 1.2.7 Extended Audio Description are not required.

Criterion	Name	Level	What it requires in practice
1.2.1	Audio-only and Video-only (Prerecorded)	A	Transcript for audio-only. For silent video, a text description or equivalent audio track.
1.2.2	Captions (Prerecorded)	A	Synchronized captions for all prerecorded audio, including speaker identification and meaningful non-speech sound.
1.2.3	Audio Description or Media Alternative (Prerecorded)	A	Either audio description of the visual track or a full text alternative.
1.2.4	Captions (Live)	AA	Real-time captions for live synchronized media such as a streamed all-hands.
1.2.5	Audio Description (Prerecorded)	AA	Audio description specifically. The text alternative allowed by 1.2.3 no longer satisfies it.
1.4.2	Audio Control	A	Audio that plays automatically for over three seconds needs a pause, stop, or volume control.
1.4.3	Contrast (Minimum)	AA	4.5:1 for normal text, 3:1 for large text (18 point, or 14 point bold).
1.4.11	Non-text Contrast	AA	3:1 for player controls, focus indicators, and meaningful graphical objects.
2.1.1	Keyboard	A	Play, pause, seek, volume, caption and description toggles, and full screen all keyboard operable.
2.1.2	No Keyboard Trap	A	Focus can move into the player and back out without a mouse.
2.2.2	Pause, Stop, Hide	A	Motion that auto-starts, runs over five seconds, and sits beside other content must be pausable.
2.3.1	Three Flashes or Below Threshold	A	Nothing flashes more than three times in any one second unless below the flash thresholds.
2.4.7	Focus Visible	AA	Every focusable player control shows a visible focus indicator.

Two notes. First, 1.4.3 governs text rendered as text. Text burned into a video frame generally falls under the incidental-content exception, so treat 4.5:1 for on-screen titles as a production standard rather than a strict pass or fail. Second, the Revised 508 Standards add a requirement WCAG does not: provision 503.4 says that where ICT displays video with synchronized audio, the controls for closed captions and audio descriptions must sit at the same menu level as the controls for volume or program selection. A buried caption toggle can fail 508 even when the caption file is perfect.

Prerecorded vs Live: Which Criteria Apply to Each

Prerecorded synchronized media (a finished training video, an explainer, a recorded webinar) must satisfy 1.2.2 and 1.2.3 at Level A and 1.2.5 at Level AA. Because 1.2.5 is required for AA conformance, a text alternative alone is not enough. You need real audio description unless every important visual detail is already spoken in the narration, which the W3C permits in its guidance on audio description.

Live synchronized media (a streamed town hall or instructor session) triggers only 1.2.4 Captions (Live) at Level AA. There is no Level A or AA audio description requirement for live content, and live audio-only falls under 1.2.9, which is Level AAA and out of scope.

Audio-only or video-only prerecorded content falls under 1.2.1 instead. Section508.gov frames this as a two-question workflow in its synchronized media guidance: sound plus video means captions and audio description, sound alone means a transcript, video alone means a text description or equivalent audio track. Captions and transcripts are not interchangeable: captions are time synchronized for people watching, while a transcript is static text serving screen reader users and search indexing.

What Are the Flashing and Contrast Thresholds?

Criterion 2.3.1 allows no more than three general flashes or three red flashes in any one-second window unless the flashing area stays below threshold. A general flash is a pair of opposing changes in relative luminance of 10 percent or more of maximum relative luminance where the darker state is below 0.80. The W3C's three flashes guidance adds an area test: flashing occupying no more than 25 percent of any 10 degree visual field passes regardless. Analyze at full screen, and while clips loop.

On contrast, semi-transparent lower thirds over moving footage are the usual failure, because effective contrast changes frame to frame.

What a VPAT Is and Why Procurement Asks for One

A VPAT, or Voluntary Product Accessibility Template, is a standardized reporting form maintained by the Information Technology Industry Council. A vendor fills it in criterion by criterion, stating whether the product supports, partially supports, or does not support each requirement, with remarks. The completed document is an Accessibility Conformance Report, or ACR, and Section508.gov recommends that any vendor marketing ICT to the federal government produce one. The template ships in editions for WCAG, the Revised Section 508 Standards, the European EN 301 549 standard, or all three.

A VPAT is a self-assessment, not a certification. No government body certifies products as 508 compliant, so be skeptical of any tool advertised as "508 certified." Specific "partially supports" entries also carry more weight with a contracting officer than a wall of unqualified "supports" claims.

How Knowlify Fits Into an Accessible Video Workflow

Accessibility gets expensive when it is retrofitted. If a video is recorded first, captions must be machine generated and corrected, the transcript assembled from them, and audio description squeezed into pauses nobody planned for.

Book a demo inverts that order. Because it builds videos from documents, the narration script exists as reviewed, editable text before anything renders. That single source is what makes the accessible deliverables cheap: the transcript is the script, caption text comes from the same words rather than a transcription pass over finished audio, and you can catch visual information the narration fails to describe while it is still a line you can rewrite. Our guide to scriptwriting for training videos covers how to write that way.

Knowlify publishes no certification claim, and no honest vendor should. Conformance depends on your script, your visual choices, and the player you publish into.

Production Checklist for a 508 Compliant Video

1. Script for the ear first, so the narration carries the essential visual information and 1.2.5 becomes a light pass instead of a rebuild.
2. Check the caption file, do not trust it. Verify speaker identification, sound effects, punctuation, and proper nouns. Our free caption accessibility checker flags long lines and dense cues in the browser.
3. Publish a transcript alongside the player, as selectable text rather than an image or scanned PDF.
4. Add audio description for visuals the narration does not cover, or extend the narration so it does.
5. Measure contrast at 4.5:1 on text and 3:1 on player controls, and screen for flashing at full screen, including looping animations.
6. Keyboard test the player end to end, and confirm caption and description toggles sit at the same level as volume, per 503.4.
7. Check the delivery path. If the video ships inside a course package, the wrapper must be accessible too. See our SCORM guide and training video guide. For other languages, start captions from a translated script, the cheaper path to multilingual localization.
8. Document the results as an ACR, not a marketing claim.

Key Takeaways

• 508 compliance for video means conforming to the WCAG Level A and Level AA success criteria, which provision E205.4 of the Revised 508 Standards incorporates by reference.
• The legal floor is WCAG 2.0 Level AA, but build to WCAG 2.1 Level AA: it is backward compatible and it is what the ADA Title II rule requires.
• Prerecorded video needs captions (1.2.2) and real audio description (1.2.5), not just a text alternative. Live video needs real-time captions (1.2.4) and no AA audio description.
• Provision 503.4 is 508-specific: caption and description controls must sit at the same menu level as volume.
• A VPAT is a self-assessment and the completed report is an ACR. No agency certifies a product as 508 compliant.

FAQ

What is 508 compliance in plain English?

508 compliance means your digital content meets a specific federal accessibility standard. Section 508 of the Rehabilitation Act requires federal agencies to make their information technology accessible, and the Revised 508 Standards define that by adopting the WCAG Level A and AA success criteria. For video: captions, audio description, a transcript, readable contrast, no dangerous flashing, and a keyboard-operable player.

Do videos need captions to be 508 compliant?

Yes. Criterion 1.2.2 requires synchronized captions for all prerecorded audio in synchronized media, at Level A, the baseline. Captions must include speaker identification and meaningful non-speech audio, not just dialogue. Auto-generated captions rarely pass on their own, because they miss punctuation, proper nouns, and speaker changes, so review and correct them before publishing.

Is audio description required for every 508 compliant video?

At Level AA, criterion 1.2.5 requires it for prerecorded video, with one exception. The W3C states that if all important information in the video track is already conveyed in the audio track, no additional audio description is necessary. That is why narration describing what viewers see is the cheapest path to conformance. Live content carries no Level AA requirement.

What is the difference between Section 508 and WCAG?

WCAG is a technical standard published by the W3C. Section 508 is United States law that adopts that standard by reference. Section 508 also adds requirements WCAG does not contain, most notably provision 503.4, which requires caption and audio description controls at the same menu level as volume. Meeting WCAG 2.1 Level AA gets you most of the way there.

Do I need a VPAT to sell video content to a government agency?

Not legally, which is why the template is called voluntary, but federal solicitations routinely ask for an Accessibility Conformance Report and you are at a disadvantage without one. Section508.gov recommends that vendors generate an ACR for any technology marketed to federal buyers. Fill it out honestly, because specific "partially supports" entries are more credible than blanket claims.

References

1. Section508.gov's laws and policies page
2. Revised 508 Standards
3. WCAG 2.1
4. web and mobile app rule
5. guidance on audio description
6. synchronized media guidance
7. three flashes guidance
8. Information Technology Industry Council
9. Accessibility Conformance Report
10. Book a demo
11. scriptwriting for training videos
12. caption accessibility checker
13. SCORM guide
14. training video guide
15. multilingual localization