Subtitle Burn-in

What Subtitle Burn-in helps you do

Burn SRT or WebVTT subtitles directly into a video so every player shows them, including apps that have no subtitle support. Load a caption file or paste the cues into the editor, adjust the wording and timing, choose a style, and export a clip with the text drawn into the picture. The original video and caption files stay on your device.

The video and captions are processed in your browser. Neither file is uploaded to Haivix.

How it works

The browser reads the cue file, validates each timestamp against the video duration and draws the active cue onto every frame while the video is re-encoded. Because the text becomes part of the pixels, it cannot be turned off or restyled later. The cue counter reports how many entries parsed successfully before the burn starts, so a malformed file is visible before the long encode rather than after it.

How to use Subtitle Burn-in

1. Load the video and add an SRT or VTT file, or paste the cues.
2. Check the parsed cue count and fix any timing warnings.
3. Edit the text, line breaks and per-cue styling if needed.
4. Set the position, size, colour and caption-box options.
5. Preview a few cues against the picture.
6. Burn the subtitles and download the captioned video.

When to use it

• Publish a clip for a platform that does not support caption tracks.
• Make a social video watchable without sound.
• Deliver a captioned file to a client who cannot add subtitles themselves.
• Lock captions into a review copy so feedback refers to exact wording.
• Add translated captions to a clip without editing the source project.

When not to use it

• Do not burn in captions when viewers must be able to turn them off.
• Do not use burn-in for an accessibility-first delivery that requires a separate caption track.
• Do not burn before the edit is final; every change means another encode.

Example

A two-minute product demo needs captions for a social feed where sound is off by default. The SRT file is loaded, two cues are retimed, and the captions are burned in at the lower third with a dark box. The same clip is also exported with a sidecar VTT file for the website, where a caption track is preferable.

What you can do with Subtitle Burn-in

• Import SRT or WebVTT cue files.
• Paste and edit cues directly in the tool.
• Adjust position, size, colour and caption box.
• Apply bold, italic or underline per cue.
• Validate timestamps before burning.
• Preview caption placement against the video.
• Keep the original audio track.

Example workflow

Edit the captions in the subtitle editor first when the timing is rough. A clean cue list burns in fewer passes and avoids re-encoding the video for every correction.

Keep a copy of the cue file next to the exported video. Burned-in text cannot be extracted later, and the source file is what you need for a translation or a platform caption track.

If the destination supports a caption track, upload the VTT there and use burn-in only for players that ignore subtitle files. Burned-in text is a fallback, not the better version for accessibility.

What to know before you start

• Burned-in captions cannot be disabled by the viewer.
• The video must be re-encoded, which takes time and introduces a small quality loss.
• Only SRT and VTT are supported.
• Very long cues can overflow the frame at large font sizes.
• Styling is applied uniformly except for per-cue weight and emphasis.
• A caption track and a burned-in version cannot be produced in the same pass.

Common mistakes

• Burning captions before checking that the cues fall inside the video duration.
• Using a font size that covers the subject of the shot.
• Forgetting that the captions are permanent in the exported file.
• Deleting the original cue file after the burn.
• Exporting the wrong file after editing a copy of the cue list.

Troubleshooting

If no captions appear, check the cue count and the timestamps. A cue that starts after the video ends will never display.

If the text is cut off at the edges, reduce the font size or enable a caption box with more padding.

If the export is slow, burn the captions after trimming to the section you need. The encoder processes every frame of the file.

If only some cues appear, check for blank lines between entries and for timing separators that use the wrong character. A malformed block is skipped without stopping the rest of the file.

Related standards and documentation

• The W3C WebVTT specification defines the VTT format and cue syntax.
• WCAG 1.2.2 covers captions for prerecorded video; a separate track is preferable when the platform supports it.