Adding Captions and Subtitles to AI Videos: A Simple Workflow That Works
A surprising number of people watch videos with the sound off: on a bus, in an office, or while scrolling late at night. Without captions, those viewers miss the whole message, and many simply scroll on. AI videos make this worse, because generated speech can be unclear and viewers have no speaker to lip-read. A simple caption workflow fixes most of this in a few minutes, and it makes your videos accessible to far more people in the process.
1. Start from the script, not the audio
The easiest captions come from a script you already have. If you wrote the narration before generating the video, you already hold the exact words, and captioning becomes a matter of timing rather than transcription. Keep the script file alongside the video project so you never have to retype it. If you did not write a script first, that is a habit worth building: our guide to planning AI videos from a script explains why scripting first improves both the video and everything that follows it, captions included.
2. Break lines the way people read
Good captions are not just accurate; they are readable at a glance. Keep each caption to one or two short lines, and break lines at natural pauses rather than in the middle of a phrase. "Fix a leaking tap / in under ten minutes" reads easily; "Fix a leaking tap in under / ten minutes" forces the eye to jump awkwardly. Aim for no more than about forty characters per line for short-form video, and let each caption stay on screen long enough to read comfortably, roughly two to three seconds for a short line.
3. Style for readability, not decoration
Caption styling should help reading, not show off. A clean, bold, sans-serif font in white with a dark outline or a semi-transparent background box works on almost any footage. Avoid thin fonts, low-contrast colour combinations, and text placed over busy parts of the image. Position captions consistently, usually near the bottom but clear of any platform buttons or overlays that might cover them, and keep the size large enough to read on a phone held at arm's length.
Word-by-word highlighting, where each spoken word changes colour as it is said, is popular for short-form video, and it can help viewers follow along. Use it sparingly, though: fast highlighting on a fast voiceover becomes hard to follow, and it can distract from the visuals. Test your styling on a real phone before publishing, not just on a large computer screen, because a style that looks clean on a monitor can be unreadable on a small display. Our guide to choosing the right clip length is a useful companion here, since pacing and caption timing go hand in hand.
4. Check names, numbers, and terms
The words most likely to be wrong in captions are the ones that matter most: names of people and places, prices, measurements, and technical terms. AI transcription tools guess these from sound alone, and they guess wrong often. Read through the finished captions once with a pen in hand, checking every proper noun and every figure against your script or source material. This single pass is the difference between captions that look professional and captions that quietly undermine your credibility.
Pay special attention to homophones: words that sound alike but mean different things. A caption that says "their" instead of "there" or turns a brand name into a common word will be noticed by viewers, and it suggests the video itself was not checked either. If you use an AI voiceover, double-check its pronunciation of key terms too; our guide to natural-sounding AI narration covers how to catch pronunciation problems before they reach the captions stage.
5. Add subtitles for other languages when it matters
Captions in the video's own language are the baseline. Subtitles in another language are a bonus that can genuinely widen your audience, but only if they are done properly. Machine-translating your captions and publishing without review is risky: jokes, idioms, and technical phrases translate badly, and a sloppy subtitle track can confuse more than it helps. If a second language matters for your audience, have a fluent speaker review the translation, even briefly, before you publish.
6. Do a final sound-off watch-through
Before you publish, watch the whole video once with the sound completely off and only the captions to guide you. This is the experience a large part of your audience will actually have, and it reveals problems nothing else does: captions that lag behind the action, text hidden behind on-screen graphics, or sections where the visuals alone do not make sense. If you can follow the video with no sound at all, your captions are doing their job.
Also watch once at normal speed with sound on, to catch timing drift, where captions gradually fall behind the speech over a longer video. Drift usually comes from a transcription that missed a pause or a repeated word, and it is easy to fix by re-syncing that section. For short-form posts, this whole check takes under a minute; for longer videos, it is still the cheapest quality step you have. Our guide to short-form social videos has more on the small checks that separate a polished post from a rushed one.
Bottom line: Work from the script, keep lines short and readable, check every name and number, and always watch the finished video once with the sound off.