Skip to Content

Digital Accessibility

Writing Closed Captions

Closed captions can be more customizable for viewers, but are not offered by all video hosting platforms. Learn how to write closed captions as a SubRip caption file.

Formatting your Caption File

SubRip Subtitle (SRT) files can be created and edited with any plain text editor. These caption files are widely supported by most video editing software and video players. You'll type what was said in your video, along with time codes for when each line of text should be displayed. 

  1. Number your captions in order, starting with 1.
  2. Indicate the start and end time of each caption.
    • Use two hyphens and a right angle bracket (-- >) to indicate a time span.
    • Stick to the timecode format: hours:minutes:seconds,milliseconds (00:00:00,000).
  3. Write your caption text.
    • To designate sounds, use square brackets. For example: [intro music].
    • Add two right arrows (>>) to identify speakers or a change of speaker.
    • Limit 40 characters per line and two lines per caption.
    • Break up caption lines at a logical point.
    • Follow additional guidelines from DCMP's Captioning Key.
  4. Add a blank line to mark the end of each caption.
  5. Save the file with UTF-8 encoding to maximize compatibility with video hosting platforms like YouTube.

SRT Sample Formatting

00:00:00,000 -- > 00:00:03,000
>> Instructor: Today we’ll be starting
the next chapter—

00:00:03,000 -- > 00:00:05,000
[student coughs]

00:00:05,000 -- > 00:00:8,000
>> Student: Excuse me, can I ask
about the homework first?

Uploading Your SRT File to YouTube

YouTube is the university’s preferred hosting platform for videos that will appear on a USC digital product.

  1. Make sure your file type is supported on YouTube.
  2. Follow the instructions on YouTube's Add Your Own Closed Captions page to upload your SRT file.

Instructions for Other Platforms

Challenge the conventional. Create the exceptional. No Limits.