Audio Joiner
Merge multiple audio files into one, in any order, right in your browser. Reorder the list, pick a format, download. Free, private, no upload.
About the Audio Joiner
This free audio joiner combines several audio files into a single continuous track. Add two or more files, drag them into the order you want with the up/down controls, choose an output format, and the tool stitches them together back-to-back. It is ideal for merging voice-memo parts, chapters of an audiobook, or a playlist into one file.
Because different files can have different sample rates and codecs, the joiner re-encodes everything to one consistent format (MP3, M4A or lossless WAV) so playback is seamless with no clicks or gaps. All of this happens in your browser through FFmpeg WebAssembly — your files are never uploaded.
The FFmpeg engine (about 30 MB) downloads from a CDN the first time and is then reused, so the first join is slower than later ones. The combined size of all files must stay under 100 MB, since the work happens in your device's memory.
How to Use the Audio Joiner
- 1Add two or more audio files (MP3, WAV or M4A) — up to 100 MB combined.
- 2Reorder them with the up and down buttons until the sequence is right.
- 3Choose the output format (MP3, M4A or WAV).
- 4Click Join Audio, preview the merged track, and download it.
Frequently Asked Questions
Is my audio uploaded to a server?
No. All files are merged in your browser using FFmpeg WebAssembly and never leave your device. Only the engine is downloaded, once.
Why is the first join slow?
The first time you use a converter here, the FFmpeg core (~30 MB) is fetched from a CDN and compiled. It is cached afterwards, so later joins are faster.
Can I join files that are in different formats?
Yes. You can mix MP3, WAV and M4A. The joiner re-encodes them all to one consistent output format so the result plays smoothly without gaps or glitches.
How do I change the order of the tracks?
Each file in the list has up and down buttons — use them to arrange the sequence before joining. You can also remove any file you added by mistake.
Is there a limit on how much I can join?
The combined size must stay under 100 MB because everything runs in your browser's memory. For very long audiobooks, join in a few batches.