Trim Audio

Features

• Cut by start and end time, accepting both `12.5` and `0:12.5`
• "Set as start / end" while previewing, so you never guess a timestamp
• Adjustable fades (0–30 s) to remove the click at the cut
• Times past the end of the audio are clamped, and the result says so
• Start after end gives an empty clip rather than an error
• Bit depth of 16-bit integer or 32-bit float
• The result reports the actual range and duration kept
• Nothing is uploaded and no server is involved; it works offline

How to use

1. Drop an audio file in
2. Play to where you want the clip to begin and click "Set as start"
3. Play to where it should end and click "Set as end"
4. Add a little fade for music or ambience; skip it for speech
5. Click Start and download the .wav

FAQ

There is a click at the cut. How do I remove it?

That is the click at the edit point: the waveform jumps from some non-zero value straight to zero, and the speaker reproduces that discontinuity as a click. Fades fix it, usually 0.05 to 0.2 seconds, longer starts eating into the content itself. Remember both ends: a fade in at the start and a fade out at the end. Conversely, if you are cutting a complete sentence (where the boundaries already sit in silence), a fade will nibble off the first and last sounds, so leave it off.

Why is the export WAV again, not MP3?

Browsers have no MP3 encoder; see the Audio to WAV tool for the details. In practice it does not matter: trimming itself is lossless, and you can convert the resulting WAV with any player — that step costs nothing, because the source already holds the full waveform. Doing it the other way round (MP3 first, then trim) is the bad order: that decodes, encodes and decodes again, losing quality at every turn.

Can I be precise to the millisecond?

You can type decimals (`12.345`), and they are converted to sample indices, so the real precision is a single sample — about 0.023 ms at 44.1 kHz, finer than a millisecond. The catch is the "Set as start" button, which can only be as precise as the playback position the browser reports (typically tens of milliseconds). When exact alignment matters, typing the number beats clicking the button.

What curve do the fades use?

Linear amplitude: the volume rises evenly from zero or falls evenly to zero, and both ends genuinely reach zero (not just "close to it"). An equal-power square-root curve is deliberately not used, because that suits crossfading two overlapping pieces (it avoids a dip in the middle), whereas a single-clip fade sounds more like "silence to sound" when it is linear — a square-root fade makes a "one second fade-in" sound much shorter than a second.

Is the file uploaded?

No. Trimming slices a sample array in memory, with no network requests, and it works offline.