What Is Closed Captioning?

Three terms get used loosely. Here are the actual definitions:

Closed captions (CC)

Stored as a separate track from the video. Viewers turn them on or off via a CC button. Designed for deaf and hard-of-hearing audiences — include speaker identification (e.g., "JOHN:"), sound effect descriptions ("[door slams]"), and music notations ("[upbeat music]"). Required by U.S. law for most TV programming, and for TV shows that are later shown online.

Open captions

Burned directly into the video picture. Always visible — viewers cannot turn them off. Used in social media (TikTok, Instagram Reels with on-screen text), public displays, theatrical screenings for accessibility, and any context where the player may not support a captions track.

Subtitles

Translation of dialogue into another language for hearing viewers who don't speak the original. Subtitles assume the viewer hears the audio. They typically don't include speaker IDs (the viewer can hear who's speaking) or sound effects (the viewer can hear them). Stored as a separate track like closed captions but editorially different.

Why the distinction matters

A subtitle file translated from English to Spanish is not closed captioning. A closed caption file in the original language is not subtitles. If a video is accessible to deaf viewers, it has closed captioning. If a video is accessible to non-English speakers, it has subtitles. A truly accessible video may have both — closed captions in the source language and subtitles in target languages.

Closed captioning is mandated by several U.S. laws and rules. Broadcast and online video are regulated separately.

Broadcast TV — FCC rules

The Federal Communications Commission (FCC) requires closed captioning for almost all programming on broadcast and cable television. The Telecommunications Act of 1996 established the foundation; subsequent rulemaking expanded coverage. As of 2026, the rules require: (a) 100% of new, non-exempt English programming to be captioned, (b) caption quality standards (accuracy, synchronicity, completeness, placement), and (c) the same 100% rule for new, non-exempt Spanish-language programming.

Online video — 21st Century Communications and Video Accessibility Act (CVAA)

The CVAA, signed in 2010, extended captioning requirements to internet video. Specifically, video that aired on TV with captions must include captions when redistributed online. Pure web-original content (e.g., a YouTube channel that never aired on TV) is not directly covered by the CVAA, but it may fall under the ADA (see below).

Public-facing websites — Americans with Disabilities Act (ADA)

The ADA's Title III applies to "places of public accommodation," which some courts have interpreted to include public-facing websites (courts are split on this). Lawsuits have been filed against companies whose video content lacks closed captioning. There is no settled legal standard for private websites, but WCAG 2.1 Level AA is the benchmark most often used. It requires captions for pre-recorded video with audio (Success Criterion 1.2.2, Level A) and for live video (1.2.4, Level AA).

Section 508 — Federal agencies

Section 508 of the Rehabilitation Act requires U.S. federal agencies to make the technology and content they use accessible. The 508 standards adopt WCAG 2.0 Level AA, which means captions on agency video.

Practical implications for content creators

If you're running a business, university, or government website with video content, closed captioning is often expected, and in many cases legally required. The cost-benefit math has flipped in 2026: AI-generated captions cost almost nothing and make a strong first draft on clear speech, so there's no realistic reason to skip captioning even for unregulated content.

The format depends on whether the captions are for broadcast TV, streaming, or web video.

Broadcast TV — CEA-608 and CEA-708

Two standards govern broadcast captioning in North America:

• CEA-608 (formerly EIA-608, "Line 21 captioning"): The original analog captioning standard, encoded in line 21 of the NTSC video signal. By default it shows white text on a black background, with only basic options for color, italics and underline, and up to 32 characters per line.
• CEA-708: The standard for digital television, introduced with HDTV. Supports more fonts, text sizes, and text and background colors (including see-through backgrounds), plus better positioning. The FCC requires digital TV sets in the U.S. to decode it.

Streaming and online video — file-based formats

Online video uses standalone caption files in formats like:

• SRT (SubRip): The most common format. Plain text with timestamps. Universally supported. See full SRT file reference →
• WebVTT (.vtt): The W3C format for HTML5 video. It is the format browsers support for the HTML <track> element.
• iTT (iTunes Timed Text): Apple's caption format for iTunes/Apple TV submissions.
• TTML / DFXP: XML-based formats used by Netflix and other streaming platforms for richer styling.
• SCC (Scenarist Closed Caption): Used in professional video workflows; mirrors CEA-608 byte data.

For most use cases (YouTube, Vimeo, your own website), SRT or VTT is the right choice. SRT for upload to YouTube/Vimeo; VTT for embedding in your own HTML5 video player.

Every modern video platform supports closed captioning. The toggle location varies:

YouTube (web, mobile, TV apps)

Click the CC button in the player controls (bottom-right). For language and font customisation, click the gear icon → Subtitles/CC → Options. YouTube's auto-captions are AI-generated and toggleable separately from creator-uploaded captions.

Netflix

Click the speech-bubble icon while playing a title. Pick from available languages and styles. Captions can be customised globally in Account → Subtitle Appearance.

Amazon Prime Video

Click the speech-bubble or CC icon in the player. Caption style settings vary by device.

Apple TV / iTunes

Use the subtitles control in the player during playback. To always show captions on Apple TV, go to Settings → Accessibility → Subtitles and Captioning and turn on Closed Captions and SDH. On iPhone and iPad, the same settings live in Accessibility → Subtitles & Captioning.

Disney+, Hulu, Max, Paramount+

All have a captions/subtitles button in the player overlay. Caption style is set in the app or in your device settings.

Broadcast TV

Press the CC button on your TV remote. If your remote lacks one, navigate to TV menu → Accessibility or Closed Captions.

Zoom, Google Meet, Microsoft Teams

All three support live AI captioning. Click the CC button (or "Show captions") in the meeting toolbar. Captions are generated in real time and disappear after the meeting unless explicitly recorded.

Three workflows, in order of effort:

1. Auto-generated captions (free, fast, needs a check)

Upload to YouTube — automatic captions are generated after upload, though they may not be ready right away. They can contain errors, but they are a workable starting point. Or use a dedicated tool like Whisper (open-source), TranscribeVideo.ai for TikTok and Instagram links (for YouTube, it reads the captions a video already has), or paid services like Otter and Rev. Export the result as an SRT file. Upload the SRT to your video host (YouTube, Vimeo, etc.) — most platforms accept SRT directly.

2. Hybrid: AI draft, human review (recommended for accessibility)

Generate AI captions, then have a person review and correct. Errors common in AI captions: proper nouns (people's names, places, brands), technical jargon, homophones (their/there), and overlapping speech. Time and cost depend on the audio and the editor, so ask for quotes. This is a common workflow in 2026 for organisations with accessibility obligations.

3. Full human transcription (expensive, gold standard)

Professional captioning services (such as 3Play Media and Rev) offer captions made or fully checked by trained people. Pricing varies by service and turnaround. Often chosen for high-stakes content (legal proceedings, broadcast). More than most content needs in 2026.

What to include in good closed captions

• Speaker identification when not visually obvious (e.g., "JOHN:", "INTERVIEWER:")
• Non-speech sounds in brackets ("[laughter]", "[doorbell rings]", "[upbeat music]")
• Music descriptions when significant ("[melancholy piano music]")
• Audience reactions ("[applause]", "[crowd cheering]")
• Off-screen sounds ("[gunshot in distance]")

Don't include: filler words ("um", "uh") unless they're meaningful, repeated stutters, or overlapping crosstalk that the speaker self-corrects.

Closed captioning was created for deaf and hard-of-hearing viewers and remains essential for that purpose. But many people who use captions today are not deaf or hard of hearing:

• Sound-off viewing: Many people scroll social feeds with the sound off. Captions are the only way the message lands for them.
• SEO benefit: Captions and transcripts turn speech into text that search engines can read. Without them, a search engine has much less text to go on, mostly the title and description.
• Comprehension: Studies on educational video show that captions improve comprehension and recall, even for viewers who can hear perfectly.
• Watch time: Captions let people follow along with the sound off, which can keep them watching longer.
• Non-native speakers: About 1.08 billion people speak English as a second language (Ethnologue, 2021). Captions make English-language content accessible to them in a way audio alone cannot.
• Public-space viewing: People watching video on a phone in a coffee shop, on a train, or in an open office mute the audio and rely on captions.

If you produce video professionally and don't caption it, you're losing a meaningful share of your audience for the cost of a few minutes of automated captioning per video.