Audio Cut and Merge takes a section out of one recording, or joins several recordings into one in a chosen order. The panel has three sub-tabs — “Cut”, “Merge” and “Pitch” — and this page focuses on the first two: cutting offers “Fast (lossless)” or “Exact (re-encode)”, and merging lets you tick several files, move them up and down, and set a silent gap between clips.

When the selected files can be joined directly and the gap is 0, the merge is a lossless stream copy; as soon as the formats differ or the gap is greater than 0, everything is resampled to 44.1 kHz stereo and re-encoded, with MP3 or M4A as the output format. The pitch tab shifts pitch with asetrate and compensates the speed with atempo, over a range of −12 to +12 semitones.

1. 01Add materialput one or more audio files into the workspace and switch to the “Audio Cut” panel.
2. 02For cutting, set the range and modedrag the start and end times; fast cutting is quick but snaps to audio frame boundaries, so choose “Exact (re-encode)” when the position has to be precise.
3. 03For merging, pick files and ordertick at least two and use move up/move down to set the play order; enter a number of seconds under “Silent gap between clips” when you want a pause.
4. 04Confirm the outputwhen the lossless conditions hold the interface says “lossless stream copy”; otherwise choose MP3 or M4A and click “Merge audio”.

Fast-cut precision

lossless fast cutting works on encoded frame boundaries, so MP3 and AAC usually have a small cut-point error; use the exact mode when the cut point matters.

Conditions for a direct copy

only compatible formats with no silent gap can be copied in seconds; mixed formats or gap > 0 force resampling and re-encoding.

Output choice

a merge that needs re-encoding offers only MP3 or M4A; exact trimming keeps the source format where possible and falls back to MP3 for formats it cannot encode.

Pitch range

only −12 to +12 semitones, with the duration compensated by atempo; it is not free-form multi-segment pitch automation.

What it does not do

there is no multi-track timeline, crossfade or sample-level waveform editing; use “Mix” to play tracks together and “Silence Remove” to take silence out.

Audio files are handled only locally in the browser by ffmpeg.wasm and are never uploaded; the first use of the workbench downloads about 31–32 MB of engine from the site's asset domain or jsDelivr.