Audio Silence Remover

Audio Silence Remover cuts the silence from the start and end of a recording, shortens long pauses inside it, and can bring its loudest moment up to one set level. It suits a voice memo with a long wait before you speak, a podcast take with gaps between answers, or a lecture clip that is too quiet. It does NOT remove noise: hum, hiss and background sound stay exactly as they were.

How to use

1. Drop one recording on the box, or click it to choose it: WAV, M4A, OGG or WebM, up to 10 minutes long.
2. Set the Threshold in dB. Sound quieter than it counts as silence; -45 dB suits a quiet room, and a noisy room needs a higher number such as -35.
3. Set the Shortest silence to cut. Pauses inside shorter than this are kept; longer ones become a quarter of a second.
4. Leave Normalise ticked to bring the loudest peak to -1 dB, or untick it to keep the volume.
5. Choose WAV, or M4A or OGG where your browser can write them, press Remove silence, then Download.

Examples

A 6-second test recording of 1 second of silence, 1 second of tone, 2 seconds of silence, 1 second of tone and 1 second of silence, cleaned at -45 dB with 0.5 seconds as the shortest silence, gives 2.25 seconds: the two tones with a quarter-second pause between them. With Normalise on, a tone that peaked at a quarter of full scale is raised by about 11 dB to peak at -1 dB.

Limits

One recording of up to 100 MB and 10 minutes, our own choices, because the whole sound is held in memory. The quarter-second pause and the -1 dB peak are our own choices too. Silence is judged in steps of a hundredth of a second, so cuts fall within that. Normalising follows the single loudest sample, so one loud click can keep the rest quiet; it does not even out loud and soft parts. Recordings with more than two channels keep the first two. M4A and OGG are offered only where the browser can encode them; WAV always works. Decoding M4A, OGG and WebM needs browser support, and the page says when it is missing. Phones have less memory than computers and may fail earlier.

FAQ

Will this clean up background noise?

No. Noise is quieter than speech but not silent, so it stays wherever there is sound. If the noise is louder than the threshold, nothing is cut either; raise the threshold a little, for example to -35 dB.

What does the threshold number mean?

It is a level in decibels below the loudest possible sound, so -60 is very quiet and -20 is fairly loud. Only stretches where every sample stays below it are treated as silence.

Is my recording uploaded?

No. A background worker in this tab decodes and rewrites the sound with the Mediabunny library and your browser, on your device. Nothing is sent to a server.