Join sound files
Joins 2 to 20 sound files, or the sound of videos, into one file in the order you choose. A pause or a smooth overlap (a crossfade) can go between them. The files are processed only on this device.
- Free
- No upload
- No sign-up
- Works offline
How to use
Press "Choose files" and pick two or more sound or video files to join (up to 20).
Set the order with "Up" and "Down", choose what goes between them and the format, then press "Join".
Press "Save" to save the joined file (joined.mp3 and so on).
Questions
Are my files sent anywhere?
No. Reading and joining the files both happen on your device. Nothing is sent out after you choose a file.
Can I join files of different formats and sample rates?
Yes. They are brought to the highest rate among them, and to stereo when any of them is stereo. The rate is changed with a filter that keeps the sound within its band.
Does the quality change?
Saved as WAV or FLAC, the quality does not change, except for files whose rate or channels were changed. Saved as MP3, M4A or OGG, the sound is encoded again, so the quality changes a little.
Do song titles and other information stay?
No. The new file holds only the sound. Song titles, artists, album pictures and other information are not copied. The file is named like "joined.mp3".
Can I use it on a phone?
Yes. Change the order with "Up" and "Down". It takes longer than on a computer, and the joined sound can be up to 2 hours. Inside apps such as LINE, saving may not work. If so, open the page again in Safari or Chrome.
Limits
- 2 to 20 files. The joined sound can be up to 12 hours on computers, and up to 2 hours on phones and tablets.
- A pause can be 0 to 10 seconds, and an overlap 0.5, 1, 2 or 3 seconds. To overlap, every file must be at least twice as long as the overlap.
- MP3, AAC, Opus and Vorbis are read with the browser's own features, so some browsers cannot read them (the tool says so when such a file is chosen). In browsers that can only read sound at once (Safari 18 and earlier on iPhone, for example) and for Vorbis, the limit is about 12 minutes on iPhone and iPad, about 24 minutes on Android and about 48 minutes on computers (in stereo at 44.1 kHz).
- A file can be up to 4 GB on computers, and up to 2 GB on phones and tablets. New files can be up to 500 MB on iPhone and iPad, 1 GB on Android, and 4 GB on computers and other devices (1 MB is 1,000,000 bytes).
- Longer files take longer. Please keep this screen open while the tool works.
- Saved as MP3, the sound starts after about 0.024 s of silence in some players (a matter of how MP3 works). For an exact length, or joins without a gap, choose WAV or FLAC.
- We cannot protect against things in your own environment, such as browser extensions.
- The work is done on this device, so how long it takes depends on how powerful the device is. On an older phone, it can take several times as long as on a computer.