Burned-in subtitles
Burn subtitles into a video on iPhone
Burning subtitles in means writing the text into the video's own pixels rather than shipping a separate subtitle file. Capster does it on the iPhone: import a clip, let the audio transcribe, style the captions, and export. What lands in your camera roll is one finished file with the words already in the picture.
vertical, square, landscape clips · iPhone, iOS 16.0+ · Updated September 2026
Burned in versus a subtitle file
Both are legitimate. They solve different problems, and the one you want depends entirely on where the video is going.
| Burned in | SRT or VTT sidecar | |
|---|---|---|
| Where the text lives | In the video frames, as pixels | In a separate .srt or .vtt file next to the video |
| Uploading to TikTok, Reels or Shorts | Works. One file is all any of them accept | No field to upload it to. The subtitles never arrive |
| Whether the viewer has to switch them on | No. They are part of the picture | Yes, where the player supports subtitles at all |
| Styling | Any font, colour, outline, background, position, animation | Text and timings. Styling is up to whatever plays it |
| Editing the words later | Re-export from the project. The old file keeps its old text | Edit the file in a text editor and re-pair it |
| Accessibility on a platform that supports captions | Not machine-readable. Add a text caption to the post as well | Readable by players and search engines that accept it |
The honest caveat: burned-in text is not machine-readable. If accessibility is the goal on a platform that supports real captions, upload a subtitle file there too, and put the key line in the post text.
How to burn subtitles in without a computer
- 1
Import the clip
From Photos or Files. All three shapes are handled: vertical, square, landscape.
- 2
Transcribe
Only the audio track is sent for speech-to-text, in any of 99 languages, detected automatically. The video never leaves the phone.
- 3
Style and place
9 presets, or set the font, size, colour, outline and position yourself. Every style control is listed here.
- 4
Export
The captions are composited into each frame and the video is re-encoded once, at full quality, straight to your camera roll.
Why the preview matches the export
Most caption tools draw the preview with the phone's UI toolkit and the export with a video compositor. The two lay text out differently, which is why captions move after a long render.
Capster runs the same compositor in both places. The frame you are looking at while you drag a caption is the frame that gets encoded, so line breaks, outline width and position survive the export exactly.
Questions people ask
What does it mean to burn subtitles into a video?
Burning subtitles in means rendering the text into the video's pixels while the file is encoded, so the words are part of the picture. There is no separate subtitle file, nothing for the viewer to switch on, and no way for a player to hide them.
Can I burn subtitles into a video on an iPhone?
Yes. Capster transcribes the audio, lets you style and correct the captions, and encodes them into the frames on the device. The finished file saves to your camera roll at full quality. No computer, no file transfer, and no account to create.
Do burned-in subtitles reduce video quality?
The video is re-encoded, so there is one generation of compression, the same as any edit that changes the picture. Capster exports at full quality and applies the same settings to free and Pro exports, so nothing about the encode depends on whether you pay.
Can I remove burned-in subtitles afterwards?
Not from the exported file — the text is part of the image. Keep the project instead. Capster saves every project on the device, so you can reopen it, change or delete the captions, restyle, and export a clean file whenever you want.
Should I burn subtitles in or upload an SRT?
Burn them in for short-form social video, where no platform accepts a sidecar file from a phone. Use an SRT for YouTube long-form, Vimeo and web players, which take the file and make the text selectable and searchable. Doing both is fine.
Posting to a specific platform? There is a page for TikTok, Instagram Reels and YouTube Shorts.
Read next
One file, subtitles included
Import, transcribe, style, export. Free to try — 5 transcriptions and clips up to 2 minutes.
Free to try: 5 transcriptions, clips up to 2 minutes, exports carry a small Capster badge. iPhone, iOS 16.0+. No account.