5 Video Captioning



Closed captioning of a video allows someone the option to turn on captioning for a video, and is a clear and effective way to make a video more accessible, reach out a larger audience, and enhance user experience. It allows disabled people such as deaf or hard of hearing people to understand the contents of the video. It also provides a resource for English learners, students or general viewers by making the content more engaging, comprehensible and interesting. In addition, search engines crawl closed captioned videos more easily to make them visible on the web.

Zoom captioning

Captions can be added to Zoom for both live and recorded events. Zoom uses automatic speech recognition technology that can be enabled by meeting hosts during meetings or webinars. If a Zoom webinar or meeting is saved to the cloud, captions can be generated for the archived video. Generally, captions generated using automatic speech recognition do not meet a level of accuracy that is suitable as an accommodation for people who depend on captions. Either edit your captions (recorded) or look into third-party captioning services (live) when an accommodation is requested.

Recorded videos


Generate auto-captions through an online tool. Both YouTube and Panopto have built in methods but there are also exterior tools such as Amara.org, DotSub.com, or Subtitle Horse. These automatically generated captions will inevitably have many errors in them, and you will need to review and edit them for accuracy.

Transcription services, such as those provided by UW-IT (for certain types of videos) will create high quality captions.


  • Transcribe content as close to verbatim as possible without making captions difficult to read
  • Spelling should be 99% correct, including names
  • Communicate non-speech sounds
  • Edit the captions so that they match what is actually being said
  • Rewatch the video with the updated captions to catch any missed errors
  • Update the caption file on your video to ensure it is the corrected version, and not the auto-captions


  • Use a non-serif font style, if given the option
  • Use 1-3 lines of text with no more than 32 characters per line
  • Sentence case should be used for readability
  • Consider using speaker labels
  • Minimum duration of a caption should be 1 second
  • Captions should be placed in the lower third of a screen or re-positioned if it will obscure onscreen text
  • Consider downloading the captions to create a standalone transcript

External Resources

Read the DCMP Captioning Key. Focus on the Elements of Quality Captioning, Language Mechanics, Sound Effects and Music, Speaker Identification, Special Considerations and the Appendix on Numbers.

This quick overview of Closed Captioning & Subtitling Standards from 3PlayMedia gives guidance on maximum length of captions per frame and how long captions should be displayed on the screen.


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Quick Tips for Accessibility Copyright © 2023 by Perry Yee; Deepa Banerjee; Kira Wyld; Artemis L.; and Jinny S. is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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