Trim Video

Cut a video to keep only the part you want — set start and end times. No upload, no server.

How to use

  1. Upload a video file (MP4 or WebM, up to 100 MB).
  2. Set the start and end times — use the built-in preview to find the right moments.
  3. Click Trim — the video is cut in your browser without re-encoding.

About this tool

This tool trims a video file to keep only the segment between the start and end times you specify. It uses stream copying (-c copy) when possible, which means the trimming is near-instant and lossless — no quality is lost because the video is not re-encoded.

The entire operation runs in your browser via ffmpeg compiled to WebAssembly. Your video is never uploaded to any server. The first use downloads the ffmpeg engine (~31 MB), cached for subsequent uses.

Stream copying works best when the start point falls on a keyframe. If the result has a few extra frames at the beginning, it is because the nearest keyframe was before your chosen start time — this is a fundamental limitation of video codecs, not a bug.

Frequently asked questions

Does my video leave my browser?

No. Everything runs locally via WebAssembly.

Why does the trimmed video start a fraction early?

Video codecs store frames in groups. Trimming can only start at a keyframe boundary, which may be slightly before your chosen start time.

Is there quality loss?

No — the tool uses stream copying, which preserves the original quality bit-for-bit.

What formats are supported?

MP4 (H.264) and WebM (VP8/VP9). The output is always MP4.

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