What does making every track equally loud do?

It measures each track's integrated loudness - how loud it sounds on average, following the EBU R128 and ITU BS.1770 standards that broadcasters and streaming services use - and changes its volume so all of them match the level you choose. A track that only needs to come up a little is not touched otherwise, and a limiter catches any peaks that would go over -1 dB.

Which loudness level should I choose?

-14 LUFS is what Spotify, YouTube and most music services play at, so it suits music and mixes. -16 LUFS is the usual level for podcasts and spoken word. -23 LUFS is the European broadcast standard, and sounds quiet next to the others. If you only want the tracks to match each other, any of them works.

Can I join MP3 files without re-encoding?

Not here: evening out the volume, crossfades and fades all change the sound, so the joined track is encoded once, at 256 kbps for MP3, which is above what most music is sold at. For a copy with no change at all, choose FLAC or WAV, which are lossless.

Can I join files of different formats?

Yes. An MP3, an M4A from a phone and a WAV can go in the same list; each is decoded and brought to 48 kHz, and a mono recording plays in both channels when the others are stereo.

Is there a limit on the number or length of files?

No set limit, and nothing is uploaded. The tracks are held in your browser's memory while you work, so a few hours of audio is comfortable on a computer.

Stays on your computer How this works

Audio joiner

Put songs, recordings or podcast segments together into one MP3, M4A, WAV or FLAC - every track made equally loud, with a gap or crossfade between them. In your browser, with nothing uploaded

Drag & drop the tracks here, or browse

MP3, M4A, WAV, FLAC, OGG, or the sound of videos · as many as you like · nothing is uploaded

About this audio joiner

Join MP3s, voice recordings, interview segments or a whole album into one file, in the order you choose. Unlike simple joiners that glue files together as they are, this one evens out the volume: each track is measured the way loudness is measured for broadcast and streaming, and turned up or down to the same level, so a quiet phone recording next to a mastered song does not make anyone reach for the volume. It is free to use, with no account and no upload limit, and it runs entirely in your browser: nothing is uploaded, and while the page stays open, a feature you have already used keeps working offline.

What you can do

Join any number of MP3, M4A, WAV, FLAC and OGG files, or the sound of videos, into one
Make every track equally loud, to -14 LUFS for music streaming, -16 for podcasts or -23 for broadcast
See each track's loudness and how much it will be turned up or down
Put a gap of silence or a smooth crossfade between tracks
Fade the whole thing in and out
Keep the peaks under -1 dB with a limiter, so the louder result never clips
Save as MP3, M4A, WAV or FLAC with a title and artist
Copy a chapter list of where each track starts, for YouTube or a podcast description

How to join audio files

Drop the tracks onto the page, all at once or a few at a time. Each is read and measured.
Put them in order with the arrows, and remove any you do not want.
Choose a loudness level, a gap or crossfade, and fades if you want them.
Choose the file type and press Join. The file downloads, and plays on the page.

Questions

What does making every track equally loud do?: It measures each track's integrated loudness - how loud it sounds on average, following the EBU R128 and ITU BS.1770 standards that broadcasters and streaming services use - and changes its volume so all of them match the level you choose. A track that only needs to come up a little is not touched otherwise, and a limiter catches any peaks that would go over -1 dB.
Which loudness level should I choose?: -14 LUFS is what Spotify, YouTube and most music services play at, so it suits music and mixes. -16 LUFS is the usual level for podcasts and spoken word. -23 LUFS is the European broadcast standard, and sounds quiet next to the others. If you only want the tracks to match each other, any of them works.
Can I join MP3 files without re-encoding?: Not here: evening out the volume, crossfades and fades all change the sound, so the joined track is encoded once, at 256 kbps for MP3, which is above what most music is sold at. For a copy with no change at all, choose FLAC or WAV, which are lossless.
Can I join files of different formats?: Yes. An MP3, an M4A from a phone and a WAV can go in the same list; each is decoded and brought to 48 kHz, and a mono recording plays in both channels when the others are stereo.
Is there a limit on the number or length of files?: No set limit, and nothing is uploaded. The tracks are held in your browser's memory while you work, so a few hours of audio is comfortable on a computer.

To cut a track first, use the Audio Trimmer; to change its key or speed, the Pitch and Tempo Changer.

Built by John McMillan, a senior full-stack engineer. Open to remote roles: hire me.

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