Custom Audio Fade Editor
Independently apply a fade-in and/or fade-out to a WAV or MP3 file, with a side-by-side preview of the original and the result so you can hear the difference before downloading.
How it works
Unlike the simple fade-in/out tool, this editor lets you independently enable or disable the fade-in and fade-out, see what percentage of the total duration each fade represents, and directly compare the original audio with the result using two side-by-side players before downloading.
Is the fade linear or exponential?
This tool applies only a linear fade: the volume changes strictly in proportion to time (a straight ramp). Some professional software also offers logarithmic or exponential curves, which sound more "natural" on long fades, but this tool doesn't implement them — we'd rather be honest than simulate a setting that doesn't actually exist here. For the vast majority of uses (avoiding a click at the start or end, joining a loop), a linear fade is more than enough.
Can I apply only a fade-out without a fade-in?
Yes: uncheck the "Fade-in" box to keep only the fade-out (or vice versa). The disabled field is simply ignored during processing.
100% local processing: any MP3 decoding and fade calculation happen entirely in your browser via WebAssembly—your audio is never sent to a server.