Closed Captions
What Closed Captions Are
Closed captions are on-screen text descriptions of a video's audio. They include dialogue, sound effects, speaker IDs, and other relevant audio cues. Their purpose is to make video content accessible for people who are deaf or hard of hearing. Unlike open captions, which are always visible, closed captions can be turned on or off by the user.
Caption Formats and Language Options
Several file formats support closed captions. For websites, common ones are SRT (SubRip), which is simple and widely supported, and WebVTT, which allows styling, positioning, and formatting. Captions may also be offered in multiple languages, increasing accessibility for non-native speakers and broader global audiences.
Captions vs. Subtitles
These terms are often confused but serve different roles. Subtitles translate spoken content for viewers who understand the visual language but not the audio language. Closed captions include both dialogue and non-speech elements intended for users who can't hear the video.
Web Accessibility Compliance
Closed captions are a requirement under the Web Content Accessibility Guidelines (WCAG) when videos convey meaningful information. They help meet accessibility standards referenced by laws like the ADA (U.S.), Section 508, and AODA (Canada). To comply with WCAG, captions must be accurate and complete, have sufficient contrast, be readable across devices, and viewers should have control to toggle captions on or off.
Broader Benefits of Closed Captions
Captions benefit more than users with hearing impairments. They improve comprehension in noisy or quiet settings, support modern viewing habits (e.g., silent auto-play on mobile), and enhance SEO by making video content discoverable through text indexing. Accurate, well-synced captions can increase engagement, accessibility, and discoverability.
Captioning in Practice
Major platforms now require or provide captions. Broadcast TV and films are mandatory under FCC and related guidelines. Streaming platforms like Netflix and Prime are required to meet ADA standards. Social media platforms like YouTube, Zoom, and Facebook offer tools or real-time captioning for improved inclusion.
The Role of Captioning Services
Professional captioning services provide transcript creation (capturing dialogue and relevant audio cues) and timing and synchronization (aligning captions with video and speech). These services combine human expertise and automation to ensure accuracy and compliance, helping content creators meet accessibility standards efficiently.