Audio tools
Cut a song down to a ringtone, make a quiet recording louder, slow a lesson down or change the format. The sound is processed on your device; nothing is uploaded.
Trim audio
Cut a song or a recording down to the part you want, picked on its waveform.
Change audio volume
Make a track louder or quieter, in decibels or as a percentage, or normalize it.
Change audio speed
Speed a recording up or slow it down, with or without keeping the pitch.
Reverse audio
Play a song, a voice or a sound effect backwards, or only a part of it.
Join audio files
Put several audio files into one, in the order you set.
Convert audio
Change audio files between MP3, WAV, M4A, OGG, Opus and FLAC, in batches.
What the audio tools do
Trim keeps the part you want, chosen on the waveform with start and end markers. Change volume makes a track louder or quieter, in decibels or as a percentage. Change speed makes it faster or slower and can keep the pitch, so a voice still sounds like itself. Reverse plays it backwards. Join puts several tracks into one file, in the order you set. Convert changes the format, with the bitrate, sample rate and channels you choose.
Input is any audio file your browser can decode: MP3, WAV, M4A (AAC) and FLAC in every current browser; OGG and Opus depend on the browser.
Formats, limits and privacy
MP3 is written with LAME, a separate WebAssembly file downloaded only when you pick MP3; WAV is written directly; the other formats (M4A, Opus and more) use your browser's own encoders, so the list of output formats can be shorter in some browsers (Firefox has no AAC encoder). To edit, the sound is decoded into memory uncompressed, tens of megabytes per minute: a computer handles long recordings, a phone much shorter ones, less again for speed changes and joins. The tool tells you before it starts rather than failing halfway, and a plain cut is copied without decoding, so it has no such limit. Everything runs in a Web Worker on your device; the network meter under each result stays at 0 B.
Which tool for what
| You want to | Use |
|---|---|
| cut a song into a ringtone or a short clip | Trim audio |
| make a quiet recording louder | Change audio volume |
| slow down a lesson or speed up a podcast | Change audio speed |
| play a sound backwards | Reverse audio |
| put several voice notes into one file | Join audio files |
| turn a WAV or M4A into MP3 | Convert audio |
| keep only the sound of a video | Extract audio from video |
Questions
- Which format should I choose?
- MP3 plays everywhere. M4A (AAC) and Opus sound the same at a smaller size. WAV and FLAC keep every sample; FLAC takes about half the space of WAV.
- Do the edits lower the quality?
- Writing a lossy format such as MP3 or AAC again loses a little each time. If you plan more edits, save the steps in between as WAV or FLAC and convert to MP3 at the end.
- Are my recordings uploaded?
- No. The file is read and processed by your browser on your device, and nothing is kept once you close the page. The network meter under each result shows the 0 B transferred while the tool worked.