Fade In & Fade Out Audio Online — Load any audio file and apply a smooth volume fade at the beginning, the end, or both. Set the fade-in and fade-out durations in seconds and pick a fade curve (linear, sine, or exponential), then download the result as WAV (lossless) or MP3. Everything runs locally in your browser.
Supported input: MP3, WAV, FLAC, OGG, Opus, M4A, AAC, WMA, AIFF and other common audio formats. Files are never uploaded to a server.
First use loads an ~30MB audio processing engine into the current browser. It is cached and reused afterwards, so please be patient.
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Click to select or drag and drop an audio file
Any common audio format; under 500MB recommended
The fade-in raises the volume from silence to full over its duration at the very start; the fade-out lowers the volume back to silence over its duration at the very end. Either can be set to 0 to skip that side.
Units: durations are in seconds (e.g. 2, 3, 0.5). The fade-in plus fade-out durations together must not exceed the total duration of the file, which is shown in the blue box above after you select the file.
Why the fade curve matters: perceived loudness is roughly logarithmic, so a linear amplitude ramp sounds like it drops too quickly at the start and then lingers near silence — that is why the Curve option also offers sine and exponential shapes, which follow perceived loudness more evenly (exponential is the usual choice for a natural-sounding fade-out on music). One related fact: joining two tracks with a hard butt-joint often produces an audible click or bump; overlapping fade-out and fade-in regions — a cross-fade — avoids it. Join tracks with Audio Merge.
