HeadStart.gov requires all video presentations to supply accessible synchronized media. Captions are responsible for combining transcripts with accurate timing to match the speed of every speaker. These guidelines will cover when captions are required, and how to produce them, to create a seamless viewing experience that is compliant with federal accessibility standards.
Accessibility Checklist
- A transcript that is verbatim, and covers all spoken dialog, including non-spoken elements.
- Captions that are time-synchronized to a source video in the same recorded language.
- Audio-only (podcasts) and presentations do not require captioning.
What are captions?
Captions are a form of synchronized text, developed from a verbatim transcript, that is designed to fit within the time constraints of a video. This is challenging to achieve, while trying to convey the intended meaning of the spoken dialogue. Captions are required to cover spoken dialogue and non-spoken elements, like sound effects and speaker IDs. The aim is to create a seamless viewing experience, for users with and without disabilities. Here are a few things to consider before you begin.
Captions Checklist
- Captions in a subrip (SRT) file format
- Spoken dialogue must be 1:1 verbatim
- Non-spoken elements (laughter, applause, and music) and Speaker IDs must be transcribed
- 80-character limit per each caption block
- Caption blocks must be on screen for a minimum of 1.5 seconds
Caption Layout
Once the transcript has been reviewed and approved, break it up into captions that will appear on screen. In the file, a captioned phrase:
- Is no more than 80 characters, including spaces (up to 40 characters per line)
- Appears on up to two lines within a single caption block
It is important to follow this guidance because phrases that exceed the limit will not render properly on screen. Follow these additional subtitling tips:
- Do not start a new sentence near the end of a caption block.
- Do not include two or more speakers in a single caption block.
- Do not separate compound words or phrases in different frames (e.g., Head Start, Early Head Start, Dr. Smith, family-centered services, the director).
- Delete spaces at the beginning or end of each line to remove the extra character.
Character Limits and Readability
The 80-character phrases should be broken into two lines that will appear simultaneously in a single caption block. Insert hard returns where the text should break in the frame rather than relying on the natural break, which may be awkward (e.g., long top line and only one or two words on the second line). In a two-line caption, each line may be up to 40 characters long, including spaces.
| DO NOT | DO |
|---|---|
| That's a great success for a program that was conceived of during | That's a great success for a program¶ that was conceived of during |
| The higher education community is also a great partner. We have — Next caption block — provided on-campus Early Head Start services at our local college; | The higher education¶ community is also a great partner. — Next caption block — We have provided on-campus Early¶ Head Start services at our local college; |
Synchronization and Timing
The first word of each captioned phrase must be synced to the audio as closely possible, and not more than a half-second off. The user needs to be able to follow the captions as they are spoken, so as not to confuse hearing people who are simultaneously using the closed subtitling function.
Captions should appear on the screen for a minimum of 1.5 seconds to ensure they meet Section 508 criteria. Captions cannot be followed if they flash across the screen too quickly.
Last Updated: March 11, 2025