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Updated 2026-06-28

How to Auto-Generate Subtitles on iPhone

By the iPhone Captions editorial team · Updated 2026-06-28

Auto-generated subtitles use speech-to-text to caption your video for you, in seconds. The main choices are where it runs (cloud vs on-device) and how much cleanup you'll do afterward.

How do I automatically generate subtitles on iPhone?

Use an app with automatic captioning: import the clip and it transcribes the speech into timed captions. Subly does this on-device (offline, nothing uploaded); Apple Clips auto-captions videos you record; Instagram, TikTok and YouTube auto-caption inside their apps. Always review the auto text — no transcription is perfect.

How auto-captioning works

An app runs speech recognition on your audio and lines the words up with timecodes. Older tools do this in the cloud (upload required); newer ones run a speech model on the iPhone itself, so it's offline and private.

Auto-generate captions on-device

  1. Import your clip. Open the app and pick the video.
  2. Generate captions. Tap to transcribe — Subly runs it locally, no upload, even in airplane mode.
  3. Review the text. Scan for misheard words, names and numbers, and fix them.
  4. Style and export. Choose a look and save with captions burned in, plus an SRT/VTT if you want.

How accurate is auto-captioning?

Good with clear audio, weaker with noise, accents, crosstalk or jargon. Expect to correct a few words every time — budget a minute of cleanup. Clean audio is the single biggest accuracy factor.

Frequently asked questions

Can iPhone generate subtitles by itself?
Not from the Photos app. You need a captioning app or a platform's built-in tool. Subly auto-generates them on-device; Clips and the social apps do it too.
How accurate are auto-generated subtitles?
Very good with clear speech, less so with noise or strong accents. Always proofread — fix names, numbers and any misheard words before posting.
Can I auto-caption without uploading my video?
Yes, with an on-device app like Subly. The speech-to-text runs on your iPhone, so nothing is uploaded and it works offline.

Related guides

Caption a video offlineCaption a video with no internet on iPhone. Most tools uploaTranscribe video to textTurn a video's speech into text on iPhone — get a transcriptAdd subtitles on iPhoneAdd subtitles to a video on iPhone three ways — the free Cli

Written for iPhone users. App features and iOS steps can change between versions — check the latest before you rely on them. How we test & our sources →