How to use it
- Drop two or more audio files.
- Put them in order with the arrow buttons.
- Choose back to back, silence or crossfade between tracks.
- Pick MP3 or WAV and click Join.
How to combine audio files
Add your files by dropping them or using the file picker; you can add more at any time. They're listed in the order they'll play; move a file up or down with the arrows, or remove it. Any format your browser can decode is accepted, and you can mix them freely: an MP3, an M4A voice memo and a WAV can go into one file. Different sample rates and mono or stereo files are matched automatically.
Click Join. The files are decoded one after another, joined, and encoded; then the result downloads and a player appears so you can listen to it right away.
Transitions between tracks
| Option | What it does | Good for |
|---|---|---|
| Back to back | Each file starts exactly where the previous one ends | Audiobook chapters, split recordings, lectures |
| Silence between tracks | Adds 0.5–10 seconds of silence | Playlists, quiz or exam audio, separate answers |
| Crossfade | The end of one track fades out while the next fades in, 0.5–8 seconds | Music mixes, workout playlists, background music |
The crossfade uses an equal-power curve, so the volume doesn't dip in the middle. It's never longer than half of the shorter neighboring track.
Output: MP3 or WAV
The joined file is saved as MP3 at 192 kbps (good quality, small, plays everywhere) or WAV (lossless, best if you'll edit it further). The file is named joined.mp3 or joined.wav.
If you need to tidy the parts first, trim them with the MP3 cutter; if some files are much quieter than others, even them out with the volume booster before joining.
Common uses
- Combine an audiobook or lecture split into many parts into one file.
- Join several voice memos or interview takes.
- Build a continuous workout or party mix with crossfades.
- Add an intro and outro jingle to a podcast episode.
- Put together listening exercises with pauses between questions.
Limits and privacy
Everything is done in your browser, so your files are never uploaded. All files are decoded into memory at once, which takes about 10 MB per minute of stereo audio. If the files together are over about 200 MB, joining can be slow and may fail on a phone; use a computer for long mixes.
Frequently asked questions
Can I merge MP3 files without re-encoding?
No, the tool decodes and re-encodes so it can add transitions and match formats. At 192 kbps the quality loss is inaudible for most listeners; choose WAV for a lossless result.
Can I combine different formats?
Yes. MP3, M4A, WAV, FLAC, OGG and even video soundtracks can be joined into one file.
How many files can I join?
There's no fixed limit; the practical limit is your device's memory.
How do I add a pause between tracks?
Choose Silence between tracks and set the length with the slider (0.5 to 10 seconds).
Are my files uploaded?
No. Joining happens entirely in your browser.
Last updated: November 12, 2026