Most short video is watched without sound, so subtitles are less of an extra than a second way of delivering the video. There are two kinds, and the difference matters when you post to more than one place.
Burned in, or optional
- Burned-in (open) captions are part of the picture. They show everywhere, on every network, whatever the viewer’s settings. You cannot turn them off, and you cannot fix a typo without exporting again.
- Optional (closed) captions are a separate track the viewer can switch on. They stay editable, and some viewers rely on them. Not every network lets you upload one, and those that generate their own may show them only in some places.
If a video goes to several networks, burning the captions in is the safe choice: one file, the same result everywhere.
Make them readable
- Two lines at most, a few words each. Break at the end of a thought, not in the middle of one.
- Big and high-contrast, with an outline or a box behind the text.
- Away from the bottom edge and the sides, where the app’s own buttons and caption sit on top.
- In time with the speech — a touch ahead rather than behind.
Check the words
Automatic captions are good enough to save an hour and not good enough to publish unread. They stumble on names, brands, product words and anything said fast. Read every line once, with the sound on, before you export. A wrong word in a caption is a wrong word on the screen.
In more than one language
If your audience speaks two languages, the subtitle is the cheapest way to serve both: speak in one, write in the other. Keep it the same way round every time, so people know where to look.
Turn the sound off and watch your own video once. If you cannot follow it, neither can most of the people who will see it.