Burned-in captions, also called open captions or hardcoded subtitles, are text drawn into the video frames. They cannot be turned off, they look the same in every player, and they work on platforms that ignore subtitle files. For short social video they are the standard: most people watch with the sound off, and captions are what keep them watching.

When to burn captions in

  • Instagram Reels, TikTok, Shorts, Stories. Subtitle files are either unsupported or hidden behind settings most viewers never open.
  • Ads and paid placements where you cannot control the player.
  • Slack, email, presentations. The video plays in a preview with no caption controls.
  • Accessibility by default. When you want to be sure the text is there, whatever the device.

When viewers might want to switch captions off, or when you want the text indexed by the platform, a subtitle file is better. YouTube is the usual example; see how to add an SRT to YouTube. You can have both from one upload.

How to burn subtitles into a video

  1. Create a free account and upload the video (up to 2 GB).
  2. Wait for the transcription. The language is detected automatically and the speech is timed word by word. You get an email when it is done.
  3. Check the text. Download the SRT and fix any names in a text editor if needed.
  4. Click Burn in. A new MP4 is rendered with the captions in the picture, and you get another email when it is ready.
  5. Download the captioned video and post it. The original file is unchanged.

What the captions look like

The captions use the style that works on short-form video: a few words at a time, large enough to read on a phone, with the word being spoken highlighted as it is said. Because the timing comes from word-level transcription rather than from subtitle cues, the highlight follows the voice exactly.

Limits
Video length up to 10 minutes
Source resolution up to 4K
Output resolution up to 1080p
File size up to 2 GB
Formats MP4, MOV, MKV, WebM and other common video formats

Longer videos are transcribed as usual and you can download the SRT and VTT files; only the burn-in step is limited.

Get the text right first

Burned-in text cannot be edited afterwards, so read the subtitles before you render. Names, product names and acronyms are the usual fixes. If a lot of words are wrong, the audio is usually the reason; the tips for accurate automatic subtitles help with the next recording.

Burned-in captions for social video

For TikTok, Reels and Shorts there are a few extra things to think about: vertical framing, keeping the text out of the area covered by the platform's own buttons, and caption length. They are covered in captions for TikTok, Reels and Shorts.