Reviewed 2026-10-20 by the Spool editorial team · How we test
Two cutting modes, and when to use each
Most video is stored as occasional full pictures (keyframes) with many frames in between that only describe changes. That's why cutting a video at an arbitrary point is harder than it looks, and why this tool has two modes.
| Frame-accurate (default) | Instant (keyframes) | |
|---|---|---|
| How | Re-encodes the kept part (H.264 at CRF 20, AAC 192 kbps for MP4) | Copies the streams without re-encoding |
| Start point | Exactly where you set it | Snaps to the keyframe at or before your start, often up to a few seconds earlier |
| Quality | Visually transparent | Bit-for-bit original |
| Speed | About as long as encoding the clip | Seconds, even for long videos |
| Best for | Social clips, precise edits, meme timing | Cutting the dead start and end off long recordings, lectures, game captures |
Instant mode only works when the original codecs fit the output container. If they don't, we fall back to frame-accurate automatically.
Setting the start and end
If your browser can preview the file (MP4 and WebM everywhere, MOV in Safari and most Chromium browsers), drag the handles on the timeline and watch the preview. For formats the browser can't preview, such as MKV, AVI or WMV, type the times instead. All of these work:
75or75.5— seconds1:15— minutes and seconds1:02:30— hours, minutes and seconds
Leave the end empty to keep everything up to the end of the video.
What format you get back
The trimmed file keeps the original format where we can write it: MP4 stays MP4, MOV stays MOV, and MKV, WebM, M4V, AVI and TS stay as they are. Other inputs come back as MP4. In frame-accurate mode, MP4 and MOV outputs use H.264 and AAC; WebM uses VP9 and Opus.
Common jobs
- Remove a long intro from a recording: use Instant. It's lossless and fast, and a second or two of slack at the start rarely matters.
- Make a 15-second clip for Stories, Reels or Shorts: use Frame-accurate so it starts on the exact beat, then resize to 9:16 if needed.
- Get under a size limit: trimming is the cleanest way to shrink a file, because it removes content instead of quality. Trim first, then compress if it's still too big.
- Cut out a middle section: trim twice (before and after the part you don't want), then join the two pieces with Merge videos.
Audio only?
For MP3, WAV or M4A files, or just the soundtrack of a video, use the audio cutter. It adds optional fade-in and fade-out. To make a phone ringtone, the ringtone maker limits the clip to 40 seconds and exports M4R for iPhone.
Troubleshooting
| Problem | Explanation |
|---|---|
| Clip starts earlier than I set | You used Instant mode, which snaps to a keyframe. Switch to Frame-accurate. |
| "The end time must be after the start time" | Check the format: 1:30 means 90 seconds, 130 means 130 seconds. |
| Frozen picture for the first moment | Some players show this with Instant cuts on files with sparse keyframes. Frame-accurate avoids it. |