Picture someone scrolling on a bus, in a waiting room, or in bed next to someone asleep. The sound is off. Your video starts, you’re clearly saying something important, and they have no idea what it is. They swipe.

Captions fix that. They also make your videos accessible to people who are deaf or hard of hearing, help everyone follow accents, fast talking and technical words, and give apps more text to understand what your video is about. Here’s how to do them well.

Why captions matter

  • Sound-off viewers. In one 2019 survey of U.S. adults, 69% said they watch video with the sound off in public, and 80% said captions made them more likely to finish a video. It’s one survey of what people say they do, but it matches what most creators see.
  • Accessibility. For deaf and hard-of-hearing viewers, captions aren’t a nice extra. They’re the video.
  • Understanding. Names, numbers, accents, noisy rooms. Text helps everyone.
  • Search. Apps read on-screen text and captions to work out what your video is about, which helps it get found.

Two kinds of captions

Burned-in (open) captions are part of the picture. You add them in your editing app and export them into the video. Everyone sees them, on every app, and you control exactly how they look. The downside: viewers can’t turn them off, and you have to keep them clear of each app’s buttons.

Closed captions are a separate text file (usually an SRT or VTT file) or the app’s own auto-captions. Viewers can turn them on and off, and the app positions them. YouTube in particular works best with a proper caption file uploaded alongside the video.

Many creators use both: burned-in captions for short vertical videos, where most people never tap a captions button, and an uploaded caption file for YouTube.

How to add captions on each app

Menus move around between updates, but the shape is the same everywhere. At the time of writing:

  • TikTok: turn on auto-captions in the editing screen before you post, then tap them to review and fix any mistakes. You can also add your own text with the text tool.
  • Instagram Reels: use the captions sticker or the auto-captions option while editing, and review the text before sharing.
  • YouTube Shorts: YouTube can auto-caption your Short, and you can add text in the Shorts editor. For full control, upload a caption file in YouTube Studio.
  • YouTube (long videos): in YouTube Studio, open the video’s Subtitles section. You can upload an SRT or VTT file, edit the auto-captions, or paste a transcript and let YouTube time it.
  • Facebook: auto-generated captions are available when you upload, and you can upload an SRT file for more control.

Whatever the app, always read the auto-captions before you post. They’re a huge time-saver, but they regularly get names, slang, accents and technical words wrong, and a wrong or embarrassing caption hurts your credibility.

Making a caption file (SRT or VTT)

An SRT file is plain text: a number, a start and end time, and the words.

1
00:00:00,400 --> 00:00:02,100
Your rice is mushy because

2
00:00:02,100 --> 00:00:03,800
of the water, not the rice.

You can type one by hand, but it’s slow. The Caption File Maker turns your script into readable caption lines, lets you tap along to the video to set the timing, and exports SRT or VTT files for any app. It runs in your browser and nothing is uploaded.

Make captions readable

Style

  • Big and bold. A plain, bold font, readable at arm’s length on a phone.
  • High contrast. White text with a dark outline or shadow, or text on a solid box. No thin text, light-on-light or fancy script.
  • Short lines. One or two lines at a time, around 30 to 40 characters per line.
  • One or two fonts across your channel. Pick them once and stick with them.

Position

  • Inside the safe zone. Keep captions away from the bottom of the frame, where every app puts the username, caption and sound label, and away from the right edge, where the buttons sit. Slightly below the center of the frame is a common spot. The Safe Zone Checker shows exactly what each app covers.
  • Not over faces or the thing people need to see.
  • Preview inside the app before posting.

Timing

  • Keep them in sync with the words.
  • Leave them up long enough. A good starting point: long enough to read each caption about three times at a normal pace. Check by watching in real time, not by scrubbing.
  • Word-by-word captions (a few words at a time, often highlighting each as it’s spoken) can hold attention well. Just don’t make them so fast or flashy that they’re hard to read or cover the action.

Captions that work for everyone

  • Caption every spoken word, not just the hook. Big words over the first few seconds are styling. Someone who can’t hear needs every line.
  • Describe important sounds in brackets: [laughter], [door slams], [upbeat music].
  • Don’t rely on color alone to mean something. Some viewers are color-blind.
  • Avoid rapid flashing text. Fast flashing can trigger seizures in some people; the web accessibility guidelines say content shouldn’t flash more than three times in any one second.

Why captions drift out of sync

Captions usually drift because the video changed after they were made: you trimmed a clip, swapped a take, or the frame rate changed on export. The fix is a habit:

  1. Caption last, after the edit is locked.
  2. Check three spots: the start, the middle and the end. If the start is right but the end is late, something changed in between.
  3. Read along with the sound on, start to finish, and fix anything missing.
  4. Check again after export, on your phone, in the app’s preview.

If an app’s auto-captions keep missing words, record a little closer to the mic and turn the music down under speech. Both help the tool hear you.

Try it

Watch your last video on your phone, muted, at arm’s length. Write down every moment you couldn’t tell what was happening. Then caption the next video before you post it, and check it the same way.