Trim and convert — files stay on your device.
Audio editing online has been awkward for a decade. The major sites either limit you to a few minutes per upload, watermark the output, or charge a subscription for what is fundamentally a few minutes of FFmpeg work. We use the same FFmpeg — but compiled to WebAssembly so it runs in your browser. Drop in a 30-minute MP3, an hour-long voice memo, an entire podcast episode in WAV. Nothing uploads. The conversion happens in a Web Worker so your browser stays responsive, and stream-copy mode (no re-encoding) makes most operations near-instant. For audio that contains private content — voice notes, interview recordings, dictation, music demos — local processing is the only sensible option.
2 audio tools.
Built for privacy, breadth, and speed.
FFmpeg-WASM, full-featured
The same FFmpeg the entire video industry uses. MP3, M4A, AAC, WAV, OGG, FLAC, OPUS — convert any format to any other with the same fidelity as the desktop binary.
Stream-copy fast path
Trimming an MP3 by 30 seconds usually takes less than half a second because we do a container-level cut without re-encoding. Same audio, different boundaries.
Waveform you can actually use
Audio Trimmer renders a peak-decimated waveform so you can drag the in/out handles to exactly the moment you want. No vague time-input boxes.
Mobile-aware
FFmpeg-WASM is a sizeable download (~25 MB) so the tool only loads it when you press the action button. Soft warning on mobile for files large enough to risk OOM.
People ask these things.
How do I trim an MP3 without uploading it?
Open the Audio Trimmer, drop your MP3, drag the in/out handles on the waveform to where you want the clip, hit Trim. The whole pipeline is FFmpeg-WASM running locally — your file never leaves the tab.
Can I convert M4A to MP3 in my browser?
Yes — the Audio Converter handles M4A, MP3, WAV, AAC, OGG, FLAC, and Opus in any direction. Stream-copy where formats are container-compatible, full re-encode otherwise.
What about long files like podcasts?
A 60-minute podcast trims in seconds (stream-copy) and converts in a few minutes (re-encode). The bottleneck is your device CPU, not network bandwidth — so a fast laptop beats a fast internet connection.
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