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As video usage continues to grow, so does the importance of video accessibility. All pre-recorded videos that are on UNC websites must be captioned. These tools help make videos and their content more accessible to both people and search engines. Also, if an iframe is used to embed a video, the code should include a title attribute. If it does not contain one, one should be added.

“An easy way to make your content more visible and readable to search engines is to provide captions for your video.”


Captions are the text version of the audio information in a video. The text synchronizes with the video’s action. They include all spoken words, identification of the speaker, and important sounds likes music or laughter. Captions benefit users who are deaf or have hearing loss, but they also help all users understand and remember information.

In addition to making video content more accessible to viewers with impaired hearing, captioning can improve the effectiveness of video.

  • Captions improve comprehension by native and foreign language speakers. A study showed 80% of people who use video captions don’t even have a hearing disability.
  • Captions help compensate for poor audio quality or background noise within a video.
  • Captions make video useful when a person has their computer muted or viewing in a noisy environment that obscures the sound. According to Digiday, a digital advertising and marketing company, up to 85% of Facebook videos are viewed with the sound off. This highlights the importance of having captions because without sound or captions, viewers will not be able to understand your video.
  • Captions improve audience comprehension of, attention to, and memory for the video. See the PubMed article, Video Captions Benefit Everyone and Oregon State University’s survey about closed captions for more information.
  • Captions increase search engine optimization. According to 3PlayMedia, “Transcripts and captions allow Google to crawl everything that is said in your video, increasing not only your keyword density, but also your keyword diversity. This allows your video to rank for a multitude of relevant terms, instead of just the prioritized terms in your video description, title, and tags. In fact, adding transcripts and captions to your videos is a proven strategy for improving SEO, views, engagement, and search rank.”
  • Captions provide viewers with a way of searching the content inside a video.

View our documentation for information on how to add captions for vendor specific software such as Panopto.

Attend the free Captioning course, offered by UNC’s Digital Accessibility Office, that shows users the ins and outs of captioning including best practices.

Lawsuit Against Harvard University

In 2015, the National Association of the Deaf (NAD) filed a class-action lawsuit against Harvard University (and MIT) for allegedly violating the Americans with Disabilities Act and the Rehabilitation Act by failing to provide accurate and comprehensive captioning for online educational videos.

After four years of litigation, the NAD and Harvard University settled. The settlement contained specific requirements for 99 percent accuracy rate on captions.

Add a Title Attribute to an Iframe

Videos are often embed on a web page using an iframe. For accessibility reasons, you should always include a title attribute for an <iframe>. This is used by screen readers to read what the content of the iframe is. For example, the iframe code from Panopto does not include the title attribute by default so you will need to add one. Simply add title="Add your descriptive title here" to the iFrame code. Be sure you replace Add your descriptive title here, with a title that properly describes the contents of the iframe. View some example code to see how a title was added to some Panopto iframe embed code.

Other Best Practices

  • Plan ahead when you are creating videos to include transcripts and captioning as part of the process.
  • Don’t auto-play videos and audio. People using screen readers navigate by listening, so any sound playing when the page loads will interfere with their experience. Audio or video should only be initiated by an action taken by the user.
  • All video controls should be accessible via the keyboard.
  • Don’t rely on sounds to convey information, like an “alert” noise.
  • Captions should appear onscreen long enough to be read.
  • One to two lines of text per caption is optimum.
  • Time captions to synchronize with the audio.
  • Ensure the font is legible and the text has enough contrast with its background.
  • Speakers should be identified when more than one person is onscreen or when the speaker is not visible.
  • Captions should normally occupy the bottom of the screen, except where they would obscure the speaker’s mouth or other vital information. It is particularly important to avoid obscuring someones face, as this conveys emotions and tone of voice, as well as being necessary for lip-reading.
  • Ensure iframe code that is used to embed a video contains a title attribute.


Q: What is the Difference Between Video Transcription and Captioning?

Video transcription is the process of producing a text document from the words spoken in a video. Transcribed text does not have a time value associated with it. In terms of accessibility, transcription works well for audio-only media, but falls short when it comes to audio with moving content on a screen, such as video.

Video captioning converts the audio content within a video into text, then synchronizes the transcribed text to the video. When the recording is played, that text will be displayed in segments that are timed to align with specific words as they are spoken. Captioning is required to make video content accessible to viewers who are deaf or hard of hearing. Captions are also considered good because they benefit a wide variety of people in different situations.

Q: What is the Difference Between Subtitles and Captioning?

Captions show the words spoken in a video in the same language, while subtitles show the translation of words spoken in a different language. The words shown on the screen in a foreign film in another language, for example, are considered subtitles.

Q: What is the Difference Between Open and Closed Captioning?

There are a few differences between open captioning and closed captioning in videos. Most notably, open captions are always on and in view, whereas closed captions can be turned off by the viewer. Open captions are part of the video itself, and closed captions are delivered by the video player or television (via a decoder). And unlike closed captions, open captions may lose quality when a video is encoded and compressed.

Related Resources & Training

Web Accessibility Perspectives: Video Captions

47 sec.

Creating Accessible Video and Audio Content

Learn strategies for improving multimedia accessibility on your websites.
4 min. 43 sec.