Audio Joiner
Join several audio files into one track. MP3, WAV, M4A, FLAC and more can be mixed, and everything runs in your browser.
Equivalent FFmpeg command
CLI command for your current settings. Updates live as you change controls.
ffmpeg -i in0.mp3 -i in1.mp3 -filter_complex "[0:a][1:a]concat=n=2:v=0:a=1[out]" -map "[out]" -c:a libmp3lame -b:a 192k output.mp3How to use
- Add your filesDrop or select two or more audio files. They appear in a list you can reorder.
- Set the orderUse the ▲▼ buttons to arrange the clips, and the remove button at the right end of a row to drop one.
- Pick the output formatMP3 to play anywhere, M4A for Apple devices, WAV to avoid any further compression loss.
- Join and downloadPress Join N files to make one track. Play it, then download.
When it goes wrong
There is a click between clips
Cause: The waveform breaks off where one clip ends and the next begins (for example, a clip cut mid-sound). Different sample rates are not the cause; the tool converts them to one rate.
Fix: Add a very short fade to the clip edges and join them again (afade on the command line).
The merge runs out of memory
Cause: A browser tab has limited memory. Larger inputs, and long audio written as WAV, use more of it.
Fix: Inputs are limited to 200 MB in total. For a long result, export MP3 or M4A.
A file was ignored when added
Cause: It was not recognized as an audio file (an unsupported extension and no file type).
Fix: Use a common format such as MP3, WAV, M4A, FLAC or OGG. For audio inside a video, extract it with the Audio Extractor first.
Questions
Can I join files of different formats?
Yes. Each file is decoded and then re-encoded into one track, so a mix of MP3, WAV and M4A works.
Does it re-encode, or join losslessly?
It re-encodes. With WAV output there is no further compression loss (it is written as 16-bit). To join files of the same format with no loss at all, use the concat demuxer command below.
How many files can I merge?
Up to 50 files at a time, and up to 200 MB in total.
Can I reorder the clips?
Yes. Use the ▲ and ▼ buttons in the list to set the order before joining.
Are my files uploaded?
No. Joining runs in your browser with ffmpeg.wasm, and nothing is sent to a server.
More detail (settings, limits, FFmpeg commands)
What each setting means
Browsers and limits
- Inputs up to 200 MB in total and 50 files.
- Inputs are re-encoded. To join files of the same format with no loss, use the CLI concat demuxer with -c copy.
The same job with the FFmpeg command line
ffmpeg -i a.mp3 -i b.wav -i c.m4a -filter_complex "[0:a][1:a][2:a]concat=n=3:v=0:a=1[out]" -map "[out]" -c:a libmp3lame -b:a 192k joined.mp3ffmpeg -f concat -safe 0 -i list.txt -c copy joined.m4a