Silence Cut Tool
Auto-detect silent gaps in video or audio and remove them in one go. Tighten up recordings and voice memos.
Local processing only — your file never leaves the browserWhat to do next
What this tool does
- Auto-detects silence with the silencedetect filter (threshold -30/-40/-50 dB)
- Minimum silence length (0.3–2 sec) keeps breath pauses while cutting long gaps
- Padding option leaves a little air around cuts to avoid jarring jump cuts
- Works on video (MP4 / MOV / WebM) and audio (MP3 / WAV / M4A)
- Shows before/after duration and reduction (e.g. 3:24 → 2:51, 16% shorter)
- Local-only processing — your file never leaves the browser
How to use
- 1
Drop the file
Drag & drop a video or audio file, up to 500 MB.
- 2
Pick threshold and minimum length
Default is -40 dB / 0.5 sec. Noisy recordings: -30 dB. Quiet studio takes: -50 dB.
- 3
Set the padding
0.15 sec (default) keeps word endings from getting clipped.
- 4
Run and download
Silence is detected, then cut in one pass. A preview and the reduction stats appear when done.
What each setting means
Recommended settings
Common pitfalls
Symptom: No silence detected at all
Cause: BGM, room tone, or hiss sits above the threshold (e.g. -40 dB).
Fix: Raise the threshold to -30 dB. If still nothing, the recording has no effective silence.
Symptom: Word endings get clipped
Cause: Zero padding removes the natural attack/decay of speech.
Fix: Set padding to 0.15–0.3 sec, or increase the minimum silence length.
Symptom: "Too many silent intervals" message
Cause: Minimum silence length is too short, so breath-level pauses are detected en masse (over 80 intervals).
Fix: Raise the minimum silence length to 1 sec or more, or lower the threshold.
Symptom: Video takes a long time to process
Cause: Video mode is two-pass: detection plus a full re-encode.
Fix: That is the cost of in-browser processing. For recordings over ~10 minutes, consider desktop FFmpeg.
Equivalent FFmpeg commands
Reference commands you can run on the desktop FFmpeg CLI.
ffmpeg -i input.mp4 -af silencedetect=noise=-40dB:d=0.5 -f null -ffmpeg -i input.mp4 -vf "select='not(between(t,5.2,8.1)+between(t,20.3,24.0))',setpts=N/FRAME_RATE/TB" -af "aselect='not(between(t,5.2,8.1)+between(t,20.3,24.0))',asetpts=N/SR/TB" -c:v libx264 -preset fast -crf 23 -c:a aac -b:a 128k output.mp4ffmpeg -i input.mp3 -af silenceremove=stop_periods=-1:stop_duration=0.5:stop_threshold=-40dB -c:a aac -b:a 192k output.m4aBrowser support & limits
- Maximum file size: 500 MB
- Processing stops if more than 80 silent intervals are detected (raise the minimum silence length)
- Video mode re-encodes with H.264 / AAC (not lossless)
- Padding applies in video mode only
Privacy
This tool runs ffmpeg.wasm directly in your browser. Files never leave your device — everything runs locally. Read the privacy policy →
Frequently asked questions
Does video quality drop?
Video mode rebuilds the timeline without the silent intervals, so it re-encodes with H.264 (CRF 23). Visually near-transparent, but not lossless. Audio mode outputs AAC at 192 kbps.
How do I choose the threshold?
Start with the default -40 dB. If nothing is detected, go to -30 dB; if speech gets cut, go to -50 dB. Aim slightly above your recording’s noise floor.
Can I use audio-only files?
Yes. MP3 / WAV / M4A are processed in a single fast pass with the silenceremove filter and exported as M4A (AAC 192 kbps).
The result feels choppy / over-cut
Increase padding to 0.3 sec and the minimum silence length to 1 sec or more. Pauses carry meaning in lectures and interviews. You can also rough-cut first with the [Trim tool](/en/tools/trim/).
Everything gets flagged as silence because the recording is quiet
Normalize loudness first with the [Volume tool](/en/tools/volume/), then run this tool — threshold detection becomes much more stable.