Web video captions
Create WebVTT captions for HTML video
Turn spoken audio into a .vtt caption file for browser-based video players. Transcription happens locally, and caption text and timing remain editable before export.
Quick answer
Whisper Online downloads a whisper.cpp model, processes the selected media locally, lets you correct individual timed words, and exports the result without uploading the media file.
Step by step
The practical workflow
- 1
Select the media source
Choose the same audio or video file used by the web player.
- 2
Create and review timed text
Run Whisper, then correct words and individual time ranges.
- 3
Export WebVTT
Choose VTT and set readable caption length, line and duration limits.
- 4
Attach the caption track
Serve the .vtt file and reference it from a track element inside the HTML video element.
WebVTT is designed for browser captions
WebVTT stores timestamped cues in a text file beginning with a WEBVTT header. Browsers can load it as a caption or subtitle track alongside HTML video.
The media and VTT file remain separate. This lets viewers enable captions when needed and allows the browser or player to render them.
A basic HTML track workflow
Place the exported VTT file on the same web origin or configure cross-origin access correctly. Add a track element with kind set to captions or subtitles, a language code, a label and the VTT source URL.
Test cue timing, text encoding, MIME type and mobile playback in the actual player before publishing.
- Use captions when the file includes dialogue and meaningful sounds.
- Use subtitles when the primary purpose is translating dialogue.
- Serve VTT as text/vtt where the hosting platform permits MIME configuration.
- Keep lines concise for narrow and responsive players.
When SRT is a better choice
Choose SRT when the destination explicitly requests it, especially a video editor or conventional subtitle import. Choose VTT for standards-based browser video. Whisper Online can export both from the same reviewed transcript.
Why use local transcription?
FAQ
Common questions
What is a VTT file?
A WebVTT file is a UTF-8 text file containing timed cues for web video and related time-aligned text.
Can browsers display VTT directly?
Browsers use VTT through a video track element or a compatible player. Opening the text file alone does not attach it to a video.
Can I export both VTT and SRT?
Yes. Review the transcript once, then download either format from the export controls.
Does Whisper Online host my VTT file?
No. The file downloads to your device; you decide where it is hosted or imported.
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