Video cutter
FileReshape's video cutter keeps the part of a video between a start and an end time and saves it as MP4 or WebM, using FFmpeg inside your browser. The video is not uploaded. Fast mode copies the video without quality loss in seconds but starts at the nearest key frame; exact mode re-encodes as H.264, which takes minutes. One part per file.
Did a file not convert correctly? E-mail [email protected], ideally with a small sample file, and it will be fixed.
Key facts
- Works with: MP4 (.mp4).
- Your files are not uploaded: the work is done in your browser, on your own device.
- File size: up to 2 GB per file (the limit of the browser's WebAssembly memory).
- Needs a current browser (Chrome, Edge, Firefox or Safari) on a computer, tablet or phone; nothing to install.
- Free to use, with no sign-up.
Why trim a video in the browser
Phone videos often start with seconds of fumbling and end with a shot of the floor, and a long recording of a school play, a match or a meeting may hold only one moment you want to share. This cutter lets you play the video, set the start and end from the current position or by typing the times, and save just that part. In fast mode the video and sound are copied, not encoded again: a cut from a one-hour MP4 is ready in seconds and looks exactly like the original. Because a video can only start cleanly at a key frame, the fast cut may begin up to a few seconds early. When the start must be exact to the frame, choose exact mode, which encodes the part again with H.264. Your video is never uploaded, which keeps family and work recordings private.
How to cut a video
- Drop the video in the box, or click to choose it.
- Play the video and use Set start and Set end, or type the times.
- Choose fast or exact cutting, click Cut video and save the file.
What to know before cutting a video
Key frames
Videos store a full picture (a key frame) only every few seconds; the frames in between only describe changes. A fast cut copies from the key frame at or before your start, so the clip can begin a moment early. Phone videos usually have a key frame every one or two seconds.
Which format you get
H.264, H.265 and AV1 videos from MP4, MOV and MKV are saved as MP4; VP8 and VP9 videos are saved as WebM. Other videos, such as old AVI or WMV files, are always encoded as H.264 MP4, and so is every exact cut.
Sound
The first sound track is kept. AAC and MP3 sound is copied into MP4 and Opus or Vorbis into WebM; other sound is converted. To remove the sound completely, use the mute video tool.
Long exact cuts
Exact mode encodes the part on your own processor: plan for one to five minutes per minute of 1080p. For a short clip from a long video it is usually quick, because only the chosen part is encoded.
About the formats
MP4
MP4 (MPEG-4 Part 14) is the most common video file format. Phones, cameras, YouTube, WhatsApp and every computer and TV use it. An MP4 is a container: the picture inside is usually compressed with H.264 or H.265 (HEVC) and the sound with AAC, and the same file can also hold subtitles, chapters and a cover image.
- The format was standardised in 2003 and is based on Apple's QuickTime format, which is why MP4 and MOV files are so alike.
- H.264 video with AAC sound plays on practically every device made in the last 15 years.
- A minute of phone video in 1080p is typically 100–200 MB; in 4K it is often 350–500 MB.
- The "faststart" layout puts the index at the beginning, so a video can start playing before it is fully downloaded.
Frequently asked questions
Is my video uploaded?
No. FFmpeg runs as WebAssembly in your browser tab and reads the video from your own disk in pieces, so files of one or two gigabytes work without any upload.
Will the quality change?
Not in fast mode: the video data is copied unchanged. Exact mode encodes the part with H.264 at a high quality setting, which looks the same to the eye.
Can I cut several parts or join clips?
The cutter saves one part per run. Cut again for another part. Joining clips needs a video editor such as Clipchamp, iMovie or Shotcut.
Does it work on a phone?
Yes, in a recent browser. Fast cuts are quick on a phone too; exact cuts of long parts are slow because the phone's processor does the encoding.