Merge audio files
Join several files into one, in any order.
How this works
- Nothing is uploaded — the file is decoded and re-encoded by your own browser, so there is no queue, no size limit beyond your device’s memory, and your recording never reaches anyone else.
- MP3 is the interesting one — no browser ships an MP3 encoder, only a decoder, which is why most free converters are servers. This loads a small encoder into the page on demand instead.
- Cutting is exact — set the start and end by ear with the player, then use the playhead button to snap a marker to where you are. What you keep is what you hear between them.
- Video files work too — drop an MP4 or a MOV and the audio track comes out on its own. The picture is discarded.
Add your files, put them in the order you want with the arrows, and get one file out. Voice notes into a single recording, chapters into one audiobook, takes into one track.
Mixed formats are fine, and so are mixed settings — which is where home-made joiners usually go wrong. If you simply staple a 44.1 kHz file onto a 48 kHz one, the second plays at the wrong speed and everyone sounds slightly off. Every file here is decoded to a common sample rate first, and a mono file among stereo ones is placed in the centre rather than hard left.
The join is seamless: files are placed exactly end to end, with no gap and no crossfade.
How to use it
- Drop in all the files, or add them a few at a time.
- Reorder them with the arrows.
- Choose an output format.
- Join and download.
Frequently asked questions
Can I mix MP3, WAV and M4A?
Yes. Each file is decoded before being joined, so the input formats are irrelevant — only the output format you pick matters.
Will there be a gap or a click between files?
No gap: the files are placed exactly end to end. A click is possible if a file ends abruptly mid-waveform, which is a property of that file rather than of the join — trimming it to a quiet moment first fixes it.
Is there a limit on how many files?
Only memory. Joining is done in one pass with the encoder controlling the pace, so long files are limited by your device rather than by an arbitrary cap.
Can I add a crossfade?
Not here. A crossfade needs a proper editor with a timeline; this is deliberately the simple case of putting one file after another.
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