How to use
- Choose several audio files; you can add more in several goes.
- Reorder with ↑ ↓ and remove clips with ✕.
- Choose back to back, silence or crossfade between clips, pick a format and click Merge and download.
Options explained
- Crossfade
- The end of one clip overlaps the start of the next by the set number of seconds, one fading out as the other fades in — good for medleys.
- Channels and sample rate
- Mono and stereo clips are combined as stereo; everything uses the sample rate the browser decoded at (usually 48 kHz).
How the length is worked out
The total length depends on what you choose under Between clips. With three clips of 60 s, 45 s and 30 s:
| Between clips | Setting | Total length |
|---|---|---|
| Back to back | none | 135 s |
| Silence | 2 seconds | 139 s (adds 2 s at each of the 2 joins) |
| Crossfade | 3 seconds | 129 s (removes 3 s at each of the 2 joins) |
A crossfade can never be longer than the shorter of the two clips it joins. If a 4 s clip is followed by a 2 s clip and you ask for 3 s, the overlap is cut down to 2 s. During the overlap the earlier clip fades out along a cosine curve while the next fades in along a sine curve (an equal-power crossfade), so the loudness stays steady instead of dipping in the middle.
Frequently asked questions
Can I mix formats?
Yes. MP3, M4A, WAV and FLAC can be combined as long as your browser can play them.
Why no MP3 output?
Browsers cannot encode MP3. Choose M4A or WAV.
Are my files uploaded?
No. Everything happens in your browser.
Privacy
This tool runs entirely in your browser. Your files and text are processed on your device and are never uploaded to our servers.