What is audio trimming?

Trimming audio means keeping one continuous part of a recording and throwing away the rest, such as the silence before a podcast starts, the applause after a song, or the 30 seconds you want as a ringtone. Cutting works the other way round: a part in the middle, such as a mistake or an ad break, is taken out and the audio on either side is joined.

Tool description

This tool trims and cuts audio files in your browser. Choose a file, drag the handles on its waveform timeline or type where the selection starts and ends, then keep the selection or remove it. Fade the result in and out, keep the original format or convert it, and download the new file. Nothing is uploaded: the audio is processed on your device with FFmpeg compiled to WebAssembly.

Features

  • Drag the start and end handles on a timeline with the waveform of the file, and zoom in for precise cuts
  • Set the start and end as seconds, mm:ss, or hh:mm:ss, with fractions of a second
  • Keep the selection, or remove it and join the parts before and after it
  • Move the playhead where the selection should start or end and set Start or End to it with one click
  • Play only the selection to check the cut before saving
  • Fade in and fade out by up to 10 seconds each
  • Keep the original format, or convert to MP3, M4A (AAC), OGG (Vorbis), WAV, or FLAC
  • In the original format, a plain cut copies the audio without re-encoding, so there is no loss in quality
  • Keeps the tags, and the cover art of MP3, M4A, and FLAC files
  • Works with MP3, M4A, WAV, FLAC, OGG, Opus, and other audio your browser can play

How it works

The tool reads the length of the file in the browser and draws its waveform from the decoded audio. When you save, FFmpeg runs on your device. A plain cut in the original format copies the compressed audio into a new file, so it is fast and lossless, and exact to a few hundredths of a second. Fades, removing a part, and converting to another format decode the audio and encode it again: MP3, M4A, and OGG at 192 kbps, WAV as 16-bit PCM, and FLAC losslessly.

Tips

  • Zoom in on the timeline with the toolbar buttons, or with Ctrl (⌘ on a Mac) and the mouse wheel, to place a cut between two words.
  • A short fade of 0.1 to 0.5 seconds removes the click a hard cut can make in music.
  • Processing happens in your browser's memory, so very long recordings can be slow or fail. Close other heavy tabs if that happens.
  • The first run downloads FFmpeg, about 30 MB. Later runs on the same page start right away.