Audio Merger: Join Audio Files with Crossfade and Fade In/Out
Pick several audio files, arrange them in the order you want and join them into a single track. Between clips you can insert a gap of silence or blend them with a crossfade, and you can also fade the whole track in at the start and out at the end. Listen to the result right away and save it as a WAV file. Everything runs in your browser, so your files are never uploaded. To change the speed or key of a single recording, use the Audio Speed & Pitch Changer; to convert to MP3, use the Video & Audio Converter.
🔒 Runs in your browser · Your data is never sent to a server
You can also drag and drop files here to add them
Merge order
No files added yet.
0 to 60. With 0, clips are joined back to back.
0 to 30. The end of one clip overlaps the start of the next. For short clips it is automatically limited to half of the shorter clip.
0 to 60. 0 turns it off. Applied to the start and end of the whole merged track.
Merged audio
How to use
- Add the files you want to join with "Choose audio files (multiple allowed)" (drag and drop also works).
- Arrange the order in "Merge order" with "Up", "Down" and "Remove".
- Pick "Join clips with", then enter the gap or crossfade length and the fade in and fade out seconds.
- Press "Merge", listen to the result, and save the WAV with "Download".
Notes
- You can add up to 20 files. The merged length is limited to 10 minutes and each file to 50 MB.
- Files with different sample rates are converted by your browser to one common rate (48000 Hz) when they are loaded, so the output WAV is 48000 Hz.
- When mono and stereo files are mixed, mono is copied to both channels. For audio with three or more channels, only the first two (left and right) are used.
- The crossfade is an equal-power one: the first clip fades down while the next fades up. If both sounds are similar, the overlap can sound slightly louder.
- The output is 16-bit PCM WAV, so it is larger than the originals. To compress it to MP3 or similar, run the saved WAV through the converter tool.
- Any format your browser can decode works (MP3, WAV, M4A, OGG and so on).
- All processing happens in your browser; the files you choose are never sent to a server.
Glossary
Crossfade
A transition where the first sound gradually gets quieter while the next gets louder, overlapping the two. It softens the jump between tracks.
Fade in / fade out
Gradually raising the volume from silence (fade in) or lowering it to silence (fade out).
Sample rate
How many times per second the sound is recorded (in Hz). A higher rate can capture higher frequencies.
WAV
A file format that stores audio uncompressed. There is no quality loss, but the files are large.
FAQ
How do I blend one track into the next smoothly?
Choose "A crossfade (overlap)" under "Join clips with" and set a length of about 2 to 5 seconds. The end of one clip overlaps the start of the next, and the volume hands over smoothly.
Why does a long crossfade not overlap as much as I set?
To keep three or more clips from overlapping at once, the overlap is automatically limited to half of the shorter of the two neighboring clips. With short sound effects, half of the shortest clip is the cap.
Can I merge files with different sample rates or channel counts?
Yes. Your browser converts everything to one common sample rate (48000 Hz) when loading. If mono and stereo files are mixed, the mono ones are copied to both channels so everything becomes stereo.
How do I fade only the very start and end of the result?
Enter seconds in "Fade in at start (seconds)" and "Fade out at end (seconds)". They apply to the start and end of the whole merged track and are independent of how clips are joined.
Is there a limit on the number or length of files?
Up to 20 files, 10 minutes of merged audio, and 50 MB per file. Everything is processed in browser memory, so merge longer material in parts. The output is WAV only.
Share this page