How to join audio files
- Add your files. Drop in two or more audio files at once. You can mix formats, such as an MP3, a WAV and an M4A.
- Set the order. Use the up and down arrows to arrange the tracks. The running total shows the length of the final file.
- Choose transitions. Add a crossfade to blend each track into the next, or a gap of silence between them.
- Join and download. Pick MP3 or WAV and press Join files.
Crossfade or gap?
A crossfade overlaps the end of one track with the start of the next while fading one out and the other in. The joiner uses an equal-power curve, so the volume stays steady through the transition. 2–5 seconds works well for a DJ-style music mix, and 0.1–0.5 seconds smooths joins between speech segments without being noticeable.
A gap inserts silence between tracks instead, which is useful for audiobook chapters, language-lesson drills or a playlist burned to one file. When the gap is set above zero, it's used instead of the crossfade.
If you set both to zero, the files are placed back to back with no pause at all, which is ideal for re-joining a recording that was split into parts.
Popular uses
- Merge the parts of a recording that your phone or recorder split into several files.
- Combine podcast segments: intro music, the interview and an outro.
- Build a continuous workout or party mix with smooth crossfades.
- Join audiobook chapters into one file for easier listening.
- Stitch several voice memos together to share as one message.
Frequently asked questions
How many files can I join?
There's no fixed limit. Because files are processed on your device, the total length you can join depends on its memory. A few hours of audio is fine on most computers.
Can I join files of different formats?
Yes. Every file is converted to the same sample rate automatically, so you can mix MP3, WAV, M4A, OGG and FLAC in one project.
What if one file is mono and another is stereo?
Mono files are converted to stereo so all the tracks match. The result sounds exactly the same.
Are my files uploaded?
No. Joining happens in your browser on your own device.