Audio & Video · Privacy-First

Audio & Video Trimmer

Drag the handles, set start and end times, and trim any video or audio clip in seconds — entirely in your browser. No account, no watermark, no upload.

100% Private · No Uploads · FFmpeg WebAssembly

Why use this trimmer?

Fast mode — instant for any size

No re-encoding means a 2 GB video trims in under a second. The bitstream is copied as-is; only the container boundaries change.

Precise mode — frame-accurate

When exact start/end frames matter (editing music, interviews), re-encode mode gives you a cut accurate to the millisecond.

Drag-handle timeline

Blue handles let you scrub the trim region directly. Click anywhere on the timeline to jump the playhead, or type exact timestamps.

Audio and video in one tool

MP4, MOV, WebM, MP3, WAV, M4A, FLAC — all handled by the same FFmpeg engine that professionals use on the command line.

Frequently asked questions

Does my video or audio get uploaded to a server?

No. All processing uses FFmpeg WebAssembly running entirely inside your browser tab. Your file never leaves your device — there are no network requests to any server during trimming.

What is the difference between Fast and Precise trim modes?

Fast mode uses -c copy to cut the file without re-encoding. It is nearly instant for any file size, but the actual cut may land up to one keyframe away from your chosen time (usually less than 1 second for video). Precise mode re-encodes the output, so the cut is frame-accurate but takes longer.

Which file formats are supported?

Video: MP4, MOV, WebM, AVI, MKV. Audio: MP3, WAV, M4A, AAC, OGG, FLAC. Fast mode outputs the same container as the input. Precise mode always outputs MP4 (for video) or MP3 (for audio).

Can I set exact start and end times by typing them in?

Yes. Click the start or end time display to edit it manually. You can type in HH:MM:SS.s format (e.g. 00:01:23.5) or MM:SS.s or plain seconds. Press Enter or click away to apply.

Why does the tool need SharedArrayBuffer?

FFmpeg WebAssembly uses multi-threading, which requires SharedArrayBuffer. This is enabled by COOP/COEP security headers on this page. If you see a browser warning, try Chrome or Firefox on desktop.

Is there a file size limit?

There is no enforced limit, but very large files (>2 GB) may exhaust browser memory. For most videos under 500 MB the tool works reliably. Fast mode is especially memory-efficient since it copies the bitstream without decoding.