Audio Trimmer
Cut a section out of an audio file against its waveform, listen to the selection before exporting, and save it with a fade that removes the click at each cut.
Cut a section out of an audio file against its waveform, with a short fade that removes the click at each cut.
Waveform
Add a file to see its waveform.
Cutting at an arbitrary point almost always lands mid-waveform, and the jump from that value to silence is heard as a click. The short fade at each end removes it, which is why it is on by default. Turn it off only if the clip is going into an editor that will crossfade it anyway.
Playback stops at the out point, so what you hear before exporting is the actual edit. The waveform is drawn from the decoded samples rather than an estimate, so silence and the gap before speech starts are exactly where they appear.
The clip is written as WAV. Browsers can decode MP3 and AAC but cannot encode them, so producing an MP3 would mean shipping a codec of several megabytes to every visitor. Everything here happens on your own machine and no audio is uploaded.
One caveat on the sample rate. Browsers decode through an audio context that resamples everything to the rate it runs at, so a file's own rate is normally lost on the way in. For a WAV it is read from the header and kept. For MP3, M4A and the rest it cannot be known without a parser for each format, so the clip comes out at your device's rate, usually 48 kHz.
About the audio trimmer
Trimming audio by typing timestamps is guesswork. The gap before speech starts, the silence in the middle and the applause at the end are all visible in a waveform and invisible in a number, which is why this draws one and lets you drag the handles against it.
You can play the selection before exporting, so what you hear is the edit rather than the whole file. That check is the step most browser trimmers leave out, and it is the one that catches a cut half a second too early.
A cut at an arbitrary point lands mid-waveform, and the jump from that value to silence is heard as a click. A ten millisecond fade at each end removes it, which is why that is on by default.
How to use it
- 1Drop in an audio file and wait for the waveform.
- 2Drag the start and end handles to the section you want.
- 3Play the selection to check the edit.
- 4Download it as a WAV.
Questions
What is the click at the start or end of my clip?
It is the cut landing mid-waveform, so the signal jumps from a non-zero value straight to silence. The short fade at each end removes it. Turn the fade off only if the clip is going into an editor that will crossfade it anyway.
Why does it export WAV rather than MP3?
Browsers include decoders for MP3 and AAC but no encoders, so producing an MP3 would mean shipping a codec of several megabytes to every visitor. WAV is what can be written honestly, and it is what editors and transcription tools want anyway.
Is my audio uploaded?
No. The file is decoded, drawn and trimmed on your own device. Nothing is transmitted.
How accurate is the trim?
To the sample. The handles move in hundredths of a second, and the export cuts at the exact frame that corresponds to.
Can I cut a section out of the middle and join the rest?
Not in one pass. Export the part before and the part after separately, then join them in an editor. This keeps one continuous selection.
Which formats can it read?
Whatever your browser can play: MP3, WAV, M4A, AAC, Ogg, Opus and usually FLAC. Not WMA, and nothing with DRM.