Audio Silence Trimmer
Automatically detect and trim leading or trailing silence from a recording, with an adjustable silence threshold.
What is Silence Trimmer?
A silence remover for voice recordings: it finds the quiet parts at the start and end of a file (and optionally between sentences) and removes them.
How it works
The waveform is split into small windows and each window's RMS level is compared with your threshold; runs longer than the minimum gap length are treated as silence. The export applies the same threshold with ffmpeg's silenceremove filter so the file matches the preview.
- Load your file. Drag a file onto the drop zone or pick one from your device. It is read locally by the browser and never uploaded.
- Set the options. Adjust the handles, format, quality or threshold controls — the preview updates as you change them.
- Process and download. Run the tool, then download the result. Compare the reported before/after size for compressors and converters.
Examples
A 42 MB podcast episode → 9 MB MP3
Trim the intro, normalise to −16 LUFS, and export at 96 kbps mono — a typical interview lands around a fifth of the original size.
A phone video with the wrong orientation
Rotate 90° and the width/height swap in the output, so it plays upright in every player instead of relying on metadata flags.
Common mistakes
Expecting instant encoders
Video encoding runs in single-threaded WebAssembly, so a clip takes roughly its own length (or a little longer) to re-encode. Stream-copy operations are near-instant by comparison.
Re-encoding when a copy would do
Trimming, removing audio and joining same-codec clips can copy streams without re-encoding — pick the copy option when it is offered to avoid any quality loss.
Ignoring the first-load download
The media engine is about 31 MB and is fetched on first use, then cached. The first conversion on a connection is slower than every later one.
Frequently asked questions
What threshold should I use?
−45 dBFS is a good starting point for speech recorded in a quiet room. Noisy recordings need a higher threshold (around −35 dBFS) so room tone is not mistaken for speech.
Will it cut off the start of words?
The minimum-gap and padding settings protect the edges of speech. Increase the padding if the first syllable feels clipped.
Can it remove every pause?
Yes — enable interior gap removal and every silence longer than the minimum is shortened to the padding you choose, which is a common podcast edit.