Video Captioning Best Practices
ADA Best Practices for Caption Timing and Positioning:
- Each caption frame should hold 1 to 3 lines of text onscreen at a time, viewable for a duration of 3 to 7 seconds. Each line should not exceed 32 characters.
- Each caption frame should be replaced by another caption.
- All caption frames should be precisely time-synched to the audio.
- A caption frame should be repositioned if it obscures onscreen text or other essential visual elements.
ADA Best Practices for Caption Style and Formatting:
- Spelling should be at least 99% accurate.
- When multiple speakers are present, sometimes it is helpful to identify who is speaking, especially when the video does not make this clear.
- Both upper and lowercase letters should be used.
- The font should be a non-serif, such as Helvetica medium.
- Non-speech sounds like [MUSIC] or [LAUGHTER] should be added in square brackets.
- Punctuation should be used for maximum clarity in the text, not necessarily for textbook style.
- Captions should preserve and identify slang or accents.