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Add subtitles to video

Caption a video automatically, fix any word, and burn the subtitles into the picture. Free, with no upload or watermark.

Files stay on your device

Drop a video to add subtitles to it

The subtitles are written from the speech on your device, so nothing is uploaded.

Any media file this browser’s engine can read.

How to add subtitles to a video

Open a video and Mastershot writes subtitles from its speech, on your device, in any of 99 languages. Fix any word, choose how they look, and save the video with the subtitles burned in, so they show on Instagram, TikTok, and everywhere else. You can also add an SRT file you already have.

  1. Step 1

    Choose a video
    Subtitles are written from its speech on your device.

  2. Step 2

    Check and style them
    Fix any word, then pick a size and a look.

  3. Step 3

    Download the video
    Save it with the subtitles burned in.

What to expect

Supported inputs
Videos with sound that this browser can read, and SRT or VTT files.
What happens
Subtitles are drawn into every frame and the video is re-encoded in its source format; the sound is copied as it is. You can also download the lines as an SRT file.
Limits
The first time, the browser downloads the 77 MB speech model and keeps it. Writing the subtitles takes about a sixth of the video's length, and burning them in re-encodes the picture.

Private by design

Your video stays on your device

Mastershot processes your file locally in this browser. It does not need to be uploaded to a server, and you do not need an account to use the tool.

  • No upload
  • No signup
  • No watermark

Questions

Yes, with no watermark, no sign-up, and no limit on length. They're made in your browser, so the video is never uploaded.

Yes. Choose Add SRT file and its lines go on the video as they are, ready to restyle.

Burned-in subtitles always show, which suits Instagram, TikTok, and WhatsApp. A separate SRT can be turned off and translated, which suits YouTube. Here you can have both.

Choose the size, the color, and a box or an outline behind the text, and move them up or down.

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