How it works
From raw video to polished, captioned clip in four steps.
Import your video
Open the editor and drag in a video file. Supported formats include MP4 and WebM. The source file stays in browser storage and is processed locally.
Generate captions
Click the generate button. With your Gemini API key, the browser sends extracted audio directly to Google Gemini for a transcript with word-level timing. You can choose English, Hinglish, Telgish, or auto-detect mode for mixed Indian-language content.
Style and edit
Choose a caption preset or customize the style manually. Adjust timing on the timeline, edit caption text, and preview the result in real time. Active-word highlighting shows exactly which word is spoken at each moment.
Export
Download the full captioned video, or export just the subtitle file as SRT or VTT. Remember to download your export before leaving the editor.
What happens after I leave?
Your project and media remain in this browser's local storage. Return with the same browser profile to continue, or delete the project to remove its local data. Downloaded exports are ordinary local files.
What about browser storage?
Project data and imported media are stored locally using IndexedDB and OPFS where available. You can delete projects in Capinsta or clear site data in browser settings.