On television, subtitles sit at the bottom and stay out of the way. On a short vertical video, captions are part of the picture. They carry the message for people watching on mute, guide the eye, and set the tone as much as the music does.
Fewer words, more often
The most common mistake is too many words at once. A full sentence across the screen is a paragraph to read; the viewer reads ahead, then waits for you to catch up.
Show two to six words at a time, in step with speech. Fast, punchy styles use two or three; calm, minimal styles can hold a short phrase.
Highlight the word that matters
In each phrase, one word carries the meaning. Colour it, enlarge it or give it a background so the eye lands on it first. Highlight sparingly: if every other word is highlighted, nothing is.
Put them where nothing else is
Centre-screen captions are bold and hard to miss; lower-third captions are calmer and leave the face clear. Either works. What does not work is the very bottom of the frame, where Reels, TikTok and Shorts draw the caption, the username and the music credit.
Choose an animation that fits the voice
- Word pop: each word appears as it is spoken. Energetic, good for fast talkers.
- Karaoke: the whole phrase is shown and each word lights up as it is said. Easy to follow for explainers.
- Line: a phrase fades in and out. Quiet and editorial.
Pick one per video and keep it. Mixing animations reads as indecision.
Make them readable
Use a heavy weight or a strong outline, a size large enough to read on a phone at arm's length, and enough contrast against every part of the frame the caption will cross. Test on a phone, not a monitor.
Proofread the transcript
Automatic transcription is very good and still mishears names, numbers and jargon. A misspelt brand name in a caption is the one error everybody notices. Read the captions once before you export.
Frequently asked questions
How many words should a caption show at once?
Two to six. Fewer words keep pace with speech and stop the viewer reading ahead; more than six turns a caption into a paragraph.
Where should captions go on a vertical video?
In the centre or the lower third of the frame, clear of the bottom edge and the right-hand side where each app draws its own buttons and text.
Are automatic captions accurate enough?
Usually, yes — but always proofread names, numbers and technical terms before exporting.