Merge Audio Files
Join several recordings into one file, in the order you want.
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or drag them here
MP3, M4A, WAV, FLAC, or OGG
- Takes
- MP3, M4A, AAC, WAV, FLAC, OGG, and Opus — mix them freely. AIFF and WMA don’t work in a browser.
- Size
- No limit. Very long files that need matching to the others just take a little longer.
Your files stay on your device
How to use it
Drop your audio files here, put them in order with the arrows, and save them as one MP3. Different formats can be mixed. Your files stay on your device.
Drop your audio files onto the box above. They’re joined in the order shown, so use the arrows to move them up or down. Then pick a quality and save one MP3.
You can mix formats freely — an MP3, a voice memo, and a WAV can all go in one file.
Files are joined back to back with no gap and no fade. If a recording ends mid-breath, that’s what you’ll hear, so trim the ends first if you want neat joins.
For the best result, pick a quality at least as high as your best file.
FAQ
Can I join different formats?
Yes. MP3, M4A, AAC, WAV, FLAC, OGG, and Opus can all be mixed. You get one MP3.
How do I set the order?
Use the up and down arrows in the list.
Is there a gap or fade between files?
No, they’re joined directly. For a pause, add a file of silence in between.
Does joining lower the quality?
Slightly, since everything is saved again as one MP3. Pick a quality at least as high as your best file.
How many files can I join?
As many as you like. Very long files just take a little longer.
How it worksFor the curious
Joining MP3s byte for byte leaves a stray header mid-file that confuses seek bars. Instead each file is decoded to raw audio, laid end to end on one timeline, and encoded once as a single MP3 by a WebAssembly build of LAME.
One track holds one sample rate and channel count, so mismatched files are matched upward to the highest rate and widest layout present — resampling the better file down would discard detail. Files already at the target stream through untouched, a few megabytes at a time.
Rates are measured by decoding a moment of each file rather than read from headers: HE-AAC (common in podcasts) declares 22,050 Hz but decodes to 44,100 Hz, and trusting the header would play it at half speed an octave down. Files that need matching are decoded whole — about 40 MB per minute of stereo.