This runs in your browser. Nothing is uploaded. Longer clips take longer here than they would on a fast server. That's the trade-off for not sending the file.
About Fade in/out
Applies FFmpeg afade at the start and end of a recording, in the browser, with no upload.
Seconds in, seconds out. The out fade starts at duration minus fade-out. If the file is shorter than the fades, it will sound like a mistake, shorten the fades. One file only; merge first if you need two recordings in a row.
Fade in/out runs FFmpeg compiled to WebAssembly in this tab. The first visit of a video or audio tool fetches about 30 MB from this origin; after that it can stay cached. Your file isn't in that download and isn't POSTed anywhere. GPL FFmpeg, single-thread, same origin, no COEP experiment. That's the same encoder as convert, trim, and compress. This page is just a different argument list, with the same honesty about what the core can't mux.
You can open the network panel and watch. Encoding a long clip on a phone is slow because it's your CPU. That wait is the trade for not handing the file to a converter you found in a search ad. Reverse and boomerang cap duration so a two-hour file doesn't try to live backwards in RAM. If a codec inside a familiar extension is missing from this core, you get an error rather than a silent broken file. Subtitle generation and stem splitting aren't here; I won't pretend they are. Missing is better than a watermarked demo.
How to use Fade in/out
- 1Drop audio.
- 2Set fade in and fade out.
- 3Click Fade, then download.
What it won't do
- One file.
- Output is MP3.
Common questions
Does fade upload the audio?
No. afade runs at the start and end of the file you dropped. The out fade begins at duration minus fade-out, so a short clip with long fades will sound wrong: shorten the fades instead of blaming the encoder.
Can I fade only the start?
Set fade out to 0. Same idea the other way: set fade in to 0 if you only want an exit. One number at zero is how you get a door on a single end.
Is this a crossfade between two files?
No. One file. Merge first if you need two recordings in a row, then fade the result. Crossfading two beds with overlapping tails is still a DAW job.
Related tools
Why this one doesn't upload your file
There is no server to upload to. This page is a static file, and the work happens in your browser using the same graphics and WebAssembly code that renders every other site you visit. Your file is read from disk into memory, processed, and handed back as a download. Once the page has loaded you can disconnect from the network entirely and it keeps working. The longer explanation