Captions and Transcripts


  • Ensures a diverse audience can view your video, including deaf and hearing impaired, people for whom English is a second language, and in situations where noise is an issue or volume is turned off
  • Increases comprehension and retention. Seeing text and hearing audio together reinforces learning concepts, fosters understanding and use of unique vocabulary terms, and helps those with learning disabilities
  • Increases Search Engine Optimization (SEO) by making content in video easier to find

Closed Captions: Adding Captions to Video

In order to caption a video, you must either own it or have permission to caption it. If you do not own the video, contact the owner for permission.

Video Captioning Service Providers

  • 3PlayMedia - full-service provider of captioning, transcription, and subtitling solutions
  • - full-service provider of captioning, transcription and subtitling solutions

Do-It-Yourself Video Captioning Tools

  • YouTube - Find out how to edit YouTube auto captions to add to your video.  
  • Amara - Online captioning tool that has free and paid versions.
  • CADET - Do it yourself captioning tool for Mac and Windows.  
  • MovieCaptioner - closed captioning software for Mac and Windows (works offline)

Guidelines for Writing Captions

Adapted from DCMP Captioning Guidelines for Educational Media

  • Place captions on the bottom two lines of the screen as long as it does not interfere with existing visuals. If there are visuals appearing on the bottom of the screen, then place captions at the top of the screen
  • Make captions two lines or less
  • Make caption length 32 characters or less per line
  • Left-align the captions
  • Divide longer sentences at a logical point where speech normally pauses
  • Use font type Helvetica medium or similar type
  • Use a translucent box so that text will be clearer, especially on light backgrounds
  • Use sans serif characters with a drop or rim shadow, and space proportionally
  • Caption higher education media at a presentation rate of approximately 120-130 words per minute. Caption theatrical presentations at a near-verbatim rate. No caption should remain on-screen less than two seconds or exceed 235 wpm
  • Editing is performed only when a caption exceeds the presentation rate limit. Edit to maintain original meaning, content, essential vocabulary, and meet presentation rate requirements

Live Captions

A live-captioned event provides accessible content to attendees with hearing impairments or for whom English is a second language.  Live captions also boost retention for the audience at large. CART (Communication Access Realtime Translation) is the term used to describe trained service providers that can create a visual transcript of audio in real-time for your audience, whether they be in attendance at your event or watching it online via a webinar platform. CART providers work live or via remote access.  Individuals seeking CART as an accommodation may visit either Disability and Access Services (MIT Students) or Human Resources Disability Services (MIT Employees and the general public).

CART providers


Transcripts provide a textual version of the content that can be accessed by anyone who cannot hear, play, or otherwise use an audio file. Transcription of audio allows users to access and read the content as text. Transcription can be done manually or through a transcription provider for a fee:

All inquiries are welcome at accessibility [at]