Audio Joiner

Add two or more audio files, drag them into the order you want with the up and down buttons, choose an output bitrate and press Join. The tool concatenates them end to end into a single MP3 and gives you the combined file to download. Everything runs on your device, so nothing is uploaded. You can add more files at any time before joining, and remove any you change your mind about.

Yes — different formats can be joined together. You can mix MP3, WAV, M4A, FLAC, Opus and other formats in the same join — the tool decodes each one and re-encodes the combined result to a single MP3, so different sample rates and formats are handled automatically. Because the output is always MP3, it plays everywhere; if you need another format afterwards, run the result through the Audio Converter.

There is no fixed limit — you can join as many files as you like. The practical ceiling is the memory available to your browser tab, because all the audio is processed on your own device. Joining a handful of songs or several voice memos is fast; combining dozens of long recordings uses more memory and takes longer, especially on a phone.

No — your audio is never uploaded to a server. Joining runs entirely in your browser with ffmpeg compiled to WebAssembly, so your files are never uploaded, logged or stored. The engine downloads once (about 10 MB) on first use, then later runs start instantly. That makes it safe for private recordings, and it works offline once the page has loaded.

The files are joined end to end with no added gap, so one plays straight into the next. If the individual recordings start or end with silence, that silence is kept — trim the ends first with the MP3 Trimmer if you want a tight join. A faint click can occur where two clips meet if they were cut at non-zero points; re-encoding to MP3 usually smooths this over.