Trim audio
HH:MM:SS start and end. Outputs MP3.
About this tool
Cut a precise section out of any audio file by entering start and end times in seconds - or by scrubbing the built-in waveform preview. Privvert's audio trimmer reads MP3, WAV, M4A, AAC, OGG, FLAC and Opus, then either copies the original audio stream losslessly (instant, zero quality loss) or re-encodes it for sample-accurate cuts when you need them.
Because the whole tool runs locally with FFmpeg compiled to WebAssembly, your recordings never leave your device. That makes it safe for client interviews, confidential voice memos, journalist source recordings and unreleased music demos. There's no upload, no signup, no waiting in a queue - drop in a file and cut.
Features
- Stream-copy mode: trims without re-encoding so the output is bit-for-bit identical to the source
- Optional re-encode mode for sample-accurate cuts inside compressed formats
- Reads MP3, WAV, M4A, AAC, OGG, FLAC, Opus and any container FFmpeg understands
- Live waveform preview so you can hear the cut before exporting
- Keeps the original codec, sample rate and channel count
- No file size limit beyond what your device's RAM can hold
- Works fully offline once the page has loaded
How to use it
- Drop your audio file onto the page or click to browse.
- Use the waveform preview to find the exact start and end of the section you want to keep.
- Type the start and end times in seconds (decimals are allowed - e.g. 12.45).
- Choose stream-copy for speed or re-encode for sample-accurate cuts.
- Click Trim and the trimmed file downloads automatically.
Everything happens inside your browser using JavaScript and WebAssembly. Your files are never uploaded to a server, never stored, and never seen by us.
Frequently asked questions
Not in stream-copy mode - the audio bytes are copied directly with no re-encoding, so output quality is identical to the source. Re-encode mode introduces a small generational loss for lossy formats like MP3, but is required when you need cuts that don't align to a keyframe.
Compressed formats like MP3 can only be cut at keyframe boundaries when stream-copying. Switch to re-encode mode for sample-accurate trimming.
There is no hard cap. Files larger than ~500 MB may be slow to load on phones because the audio has to fit in browser memory.
No. Everything happens in your browser tab; nothing is uploaded or logged on our side.