Join Audio Files
Put audio files together in the order you choose, with an optional gap between them.
What it does
Join Audio Files works on MP3, WAV, M4A, OGG, FLAC, AAC and OPUS with ffmpeg and audio engines compiled for the browser, so the recording or video is processed by your own computer or phone — the same programs a desktop editor uses, without installing one.
When you need it
Usually right before sending or publishing: a video too heavy for WhatsApp, a voice note full of hum, a clip that needs captions because the feed plays it muted, an interview to turn into text.
Limits and caveats
Long or high-resolution files take as long as your device needs, and a phone is slower than a laptop. The engines download once, the first time, and come from KIVO itself. The original file is never changed: you always download a new one. Everything happens in your browser, so the file never leaves your device.
How to join audio files
- Drop the files.
- Put them in the order you want.
- Join, and download one file.
Everything happens on this device: no file is uploaded and nothing leaves the browser.
Frequently asked questions
- Can I mix formats?
- Yes — an MP3, a WAV and an M4A join fine. They are decoded and re-encoded to one format, which is slower than a straight copy and is the only thing that works when the inputs disagree.
- Why would I want a gap?
- A second of silence between recordings is the difference between a compilation and a jump cut. For chapters of an audiobook or separate takes it is usually worth it.
- Do my files get uploaded?
- No. This tool runs entirely in your browser, so the file never leaves your device.