Two ways to cut a video: fast and exact
Compressed video doesn't store every frame as a full picture. Every so often there's a keyframe, a complete image, and the frames in between only store what changed since the previous one. That makes files small, but it means a frame in the middle of a group can't be decoded without the keyframe before it.
The fast cut (the default) works with that structure. It copies the original frames without decoding them, starting at the keyframe just before your start time. It's nearly instant and loses no quality at all. The frame-exact cut decodes the video and re-encodes your clip from exactly the frame you chose, which takes longer but starts precisely where you asked.
When should I use Frame-exact cut?
The fast cut can start up to one keyframe interval early. How far that is depends on what recorded the video:
- Phone camera footage usually has a keyframe every 1–2 seconds, so the fast cut is close enough for most clips.
- Screen recordings, game captures and videos exported by editing apps can have keyframes 5–10 seconds apart. Here, exact mode makes a visible difference.
- For a clip that must start on a specific word or beat, such as a quote, a reaction or a ringtone-style loop, use exact mode.
- For trimming the boring start and end off a long recording, the fast cut is ideal: it's instant and keeps the original quality.
How do I set the start and end precisely?
Play the video in the preview and pause where the clip should begin, then tap Set start to the current frame. The field fills in with minutes and seconds to a tenth of a second. Do the same for the end. You can also type times directly: 1:05, 65 and 0:01:05 all mean the same moment, and decimals like 12.5 work too.
Leave End empty to keep everything from the start time to the end of the video. Leave Start empty to begin at the very first frame. To check your selection before cutting, drag the preview's playhead to each time and watch a second or two.
What format is the cut video?
The fast cut keeps your original format: an MP4 stays MP4, a MOV stays MOV, a WEBM stays WEBM, and video and audio are copied untouched. The exact cut produces an H.264 MP4 at high quality (CRF 20), and audio that isn't already AAC is converted to AAC, so the result plays everywhere.
Either way, only the main video and audio tracks are kept. Subtitle and data tracks are dropped, which avoids playback problems in apps that don't expect them.
Common uses
A few of the jobs people use the cutter for most:
- Trimming dead air from the start and end of a meeting or lecture recording before sharing it.
- Pulling a highlight out of a long gameplay or sports video for social media.
- Cutting a long phone video into a short clip that fits a messaging app's limit.
- Taking a short sample of a video to show someone, without sending the whole file.
- Cutting audio too: choose an MP3 or M4A and it's trimmed the same way. The Audio Cutter page is set up specifically for that.
No upload, no watermark
The cutter runs ffmpeg inside your browser. Your video is read from your device and the clip is created in memory, so nothing is uploaded and nothing is stamped on the result. Because the fast cut doesn't re-encode, it's also one of the few ways to trim a video online without any quality loss, even on a phone.