Are the fades linear or curved?

Linear gain ramps via GainNode.linearRampToValueAtTime. That is the cleanest default for speech and most music.

Can fade-in and fade-out overlap?

No — the tool caps each fade so the combined length never exceeds the total duration.

No. Gain scaling is lossless; the only quality change comes from the final MP3 encode if you pick that format.

Fade In/OutLocal

Add smooth fade-in and fade-out effects to your audio files.

Drop an MP3 or WAV file here

or click to browse

⎆Your audio never leaves your browser. All processing happens locally.

How to use Fade In/Out

Drop a file
Drag an MP3 or WAV onto the dropzone. The original waveform renders when decoding finishes.
Set fade-in
Use the fade-in slider to choose a ramp length from 0 to 10 seconds.
Set fade-out
Do the same for the fade-out at the end of the clip.
Preview
Play the result to hear the fades applied before export.
Export
Choose MP3 or WAV and download the faded file. Everything runs locally.

Frequently asked questions

Are the fades linear or curved?: Linear gain ramps via GainNode.linearRampToValueAtTime. That is the cleanest default for speech and most music.
Can fade-in and fade-out overlap?: No — the tool caps each fade so the combined length never exceeds the total duration.
Does fading reduce audio quality?: No. Gain scaling is lossless; the only quality change comes from the final MP3 encode if you pick that format.