CATHODE

NO SIGNAL
GitHub

NO SIGNAL — DROP A FILE

or click to choose — MP3, WAV, AAC, FLAC, OGG, M4A

See any audio file, then cut it down to size

Cathode is a browser tool for podcasters, musicians, and anyone who needs to trim or convert a short recording without uploading it to a server. Drop a file in, read it, cut it, and export it, all in this tab.

How it works

  1. Drop an audio file onto the panel, or click to choose one. MP3, WAV, AAC, FLAC, OGG, and M4A all work.
  2. Zoom and pan the waveform (scroll, pinch, or the +/- keys) to find the part you want.
  3. Drag the amber handles to set the in and out points, and press play to preview the selection.
  4. Pick a format and press Export. The trimmed clip downloads straight to your machine.

Questions

Is my audio uploaded anywhere?
No. Decoding, analysis, trimming, and encoding all run in your browser tab. The only thing Cathode fetches is the ffmpeg.wasm engine on your first export, and your browser caches it after that.
What formats can I open and export?
Open MP3, WAV, AAC, FLAC, OGG, and M4A. Export to MP3, AAC, or WAV. Common formats decode natively; anything the browser cannot read falls back to ffmpeg.wasm.
Is there a file size or length limit?
Cathode loads the whole file into memory, so it is built for clips rather than feature-length recordings. A song, a voice memo, or a podcast segment is the sweet spot.
Do I need an account or an install?
Neither. It is a single static web page. Open it and start dropping files.
Does it work on my phone?
Yes. The layout adapts to phone width and the trim handles respond to touch, though large files are more comfortable on a desktop.