How to add captions to a video on iPhone

Captions aren't optional anymore. A huge share of short-form video is watched on mute — in bed, on the train, in a meeting — so a clip without subtitles loses people in the first second. Captions also make your videos accessible, boost watch time, and help the algorithm understand what you're saying.

The good news: you don't need a desktop editor or any timeline skills to caption a video on your iPhone. This guide covers every realistic method, then walks through the fastest one — automatic, on-device captions that keep your footage private.

First: burned-in captions vs. platform auto-captions

There are two different things people call "captions," and the difference matters:

• Burned-in (open) captions are drawn onto the video pixels themselves. They're always visible, in your style, and they travel with the file wherever you post it.
• Platform captions — TikTok's auto-captions, Instagram's caption sticker, YouTube's CC — are generated by each app. They use that app's look, can be toggled off by the viewer, and don't follow the file when you cross-post.

For short-form video, burn them in. You want subtitles that show the instant a clip autoplays on mute, look the same on every platform, and don't depend on a viewer flipping a setting.

Method 1 — Auto-caption app (fastest, recommended)

This is what most creators use, because it removes the two slow parts of captioning: typing and timing. A good app transcribes your speech, times each line to the word, and lets you export a finished clip.

Here's the flow with Just Captions, which runs entirely on your device:

1. Add your clipOpen the app and drop in a video, or pick up to 20 from your camera roll. Portrait, square and landscape all work.
2. Let it transcribeIt listens, transcribes the speech on your iPhone, and times clean subtitles to every word. It understands 50+ languages and captions in whatever is spoken.
3. Fix anything trickyTap a line to correct a name, brand or bit of slang. AI Correct fixes a misheard word everywhere it appears, and you can save your own terms to a personal dictionary.
4. Pick a styleChoose from four readable presets sized for vertical video, so the text never lands under the platform UI.
5. Export & postExport an MP4 with the captions burned in and upload it straight to TikTok, Reels or Shorts.

Because everything happens locally, your footage is never uploaded to a server — and it keeps working with no signal at all. Want to feel it first? The free online subtitle tool captions a clip right in your browser, no install.

Method 2 — iPhone's built-in options

People often ask whether iOS can just do this. Partly. iOS has Live Captions and can transcribe audio in apps like FaceTime and Voice Memos, and Apple Clips can add "Live Titles" as you record. But the Photos app cannot burn subtitles onto an existing saved video, and Live Captions are a system accessibility feature — not something exported into your clip.

So the built-in route works only if you're recording fresh in Clips and are happy with its title style. For an existing clip in your camera roll, you'll need a dedicated app.

Method 3 — A video editor (most control, most effort)

Editors like CapCut or iMovie let you add text manually, frame by frame. You get total control over styling, but you're typing every line and dragging it to the right timestamp — slow for anything longer than a few seconds, and painful across a batch of clips. Use this when you need bespoke motion graphics, not routine subtitles.

How to make captions people actually read

Whatever tool you use, a few rules keep subtitles legible:

• High contrast. A solid fill or a strong outline survives busy, bright footage. Thin text with no background disappears.
• One or two short lines. Big blocks of text get skipped. Keep it glanceable.
• Mind the safe zone. Keep captions clear of the bottom and right of the frame, where the platform stacks its buttons and your text gets covered.
• Don't over-animate. Bouncing, neon, word-by-word effects look busy and hurt readability. Clean beats flashy.

Readable captions aren't about looking fancy — they're about a viewer understanding your hook before they decide to keep watching.

Platform-specific placement

Each app covers a different part of the frame with its own UI. We've got a short, specific guide for each:

• Add captions to a TikTok video — clear the bottom caption row and the right-side icons.
• Add captions to Instagram Reels — stay out of the top ~14% and bottom ~35%.
• Add captions to YouTube Shorts — keep text above the title row and clear of the action column.

The bottom line

For a one-off clip you're recording fresh, Apple Clips is fine. For real, repeatable captioning of clips already on your phone — especially if you post often or care about privacy — an on-device auto-caption app is the fastest, cleanest route. Drop in a clip, let it write the captions, post in a minute.