How to Add Subtitles to a Video
Producing a subtitle file from a transcript and adding it to YouTube, a web player or a video editor — and when to burn captions in instead.
The Scriptorium team ·
Subtitles come from a transcript. Transcribe the video, correct the text, export SRT or WebVTT, then attach that file wherever the video plays. The only real decision is whether the subtitles should be a separate track or burned into the picture.
Step 1: get an accurate transcript
Upload the video to video to text and read the transcript with the audio playing. Correct it now rather than later — fixing a subtitle file after the fact means editing timed fragments one at a time, which is considerably worse.
Prioritise names, product terms and numbers. Those are both the most likely errors and the most visible ones when they appear on screen.
Step 2: export SRT or WebVTT
- SRT if you are unsure. It is accepted almost everywhere.
- WebVTT for HTML5 video on the web, and for YouTube.
Step 3: add it to the video
YouTube
- Open YouTube Studio and go to Subtitles.
- Select the video, then Add language if the language is not listed.
- Choose Upload file, select With timing, and pick your SRT.
- Review and publish.
Your uploaded track replaces the automatic captions, which is worth doing on any video where names or technical terms matter.
A website
Use the HTML5 <track> element with your WebVTT file:
<video controls>
<source src="talk.mp4" type="video/mp4">
<track src="talk.vtt" kind="captions" srclang="en" label="English" default>
</video>Use kind="captions" rather than kind="subtitles" when the track is for accessibility and includes non-speech sound.
A video editor
Most editors import SRT directly and place it as a text or caption layer. From there you can style it and, if you need to, render it into the picture.
Vimeo, LinkedIn and the rest
Almost every platform that hosts video accepts an SRT upload alongside it. Look for captions or subtitles in the video's settings after upload.
Separate track or burned in?
| Separate track | Burned in | |
|---|---|---|
| Viewer can turn off | Yes | No |
| Works on muted autoplay feeds | Often not | Always |
| Can be translated later | Yes | No |
| Readable by search engines | Sometimes | No |
| Needs re-rendering to change | No | Yes |
Rule of thumb: burned-in for social feeds that autoplay muted, a separate track for everything else. A separate track is the accessible choice, because the viewer keeps control.
Scriptorium produces the subtitle file. Burning captions into the picture happens in your video editor or on the platform, not here.
Making subtitles readable
- Two lines at most on screen at a time.
- Roughly 32 to 42 characters per line.
- Break at natural phrase boundaries, not mid-phrase.
- Leave each caption on screen long enough to read — about a second minimum.
- Keep the text in sync with the audio rather than slightly ahead.
Exported SRT and WebVTT follow segment boundaries from the transcript, which is usually close to right. For broadcast-standard subtitling you will want to adjust the splits by hand in a subtitle editor.