Add a fade in and fade out. Without opening Audacity.

Set the seconds, drop the file, download the smoothed version. Equal-power cosine curve, the kind every DAW uses by default. Works on MP3, WAV, M4A, anything your browser can decode.

drop your audio file

MP3, WAV, M4A, FLAC, OGG. One file at a time (settings are per-file).

Common fade lengths

What an "equal-power cosine" fade actually is

A linear fade scales the volume by a straight line from 0 to 1. Sounds rushed at the start and sluggish at the end because perceived loudness isn't linear with amplitude.

An equal-power fade follows a cosine curve (cos² to be precise) that keeps perceived loudness even across the fade region. It's the default in Pro Tools, Logic, Reaper, Ableton — basically every DAW. We use it here so the result sounds like a professional fade, not a calculator's idea of one.

When to use fades vs hard cuts

Hard cut: sample chops, drum hits, anywhere you want energy. Fade: anywhere the abrupt cut creates a click, pop, or jarring silence. If your audio has any room tone or DC offset, you almost always want at least a tiny fade (50-100 ms) at both ends to avoid an audible click.

FAQ

Will the file stay the same length?

Yes. Fades modify the volume of existing audio — they don't trim or extend the file. The total duration is unchanged.

How do I just add a fade-out without a fade-in?

Set the fade-in to 0. Only the fade-out applies.

What if my fade-in plus fade-out is longer than the file?

We'll cap them at half the file duration each, so they never overlap into a weird mid-file dip. We'll also warn you in the status text.

Why is the output an MP3 by default?

Most people start with MP3 and want MP3 back. Pick WAV if you need lossless (handing it off to a DAW, or applying more processing later).

Can I do a fade in the middle of the file?

Not on this tool — that's a more general edit. Use our audio cutter to split, then re-join with crossfade in our audio joiner.

Does my audio get uploaded?

No. The fade math and re-encoding happen in your browser tab.

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