Audio Fade In & Out
Processed locally in your browser — nothing is uploaded.
Quick answer
A fade-in ramps the volume up from silence at the start; a fade-out ramps it down to silence at the end. Fades stop tracks from beginning and ending abruptly, and they kill the clicks you get when a waveform is chopped mid-cycle. This tool lets you set each fade’s length in seconds and applies them in your browser, nothing uploaded. First use downloads the ~10 MB engine once, then caches it.
How to audio fade in & out
Load the audio
Drop in the file you want to fade. Its waveform is shown so you can see the start and end.
Set the fade lengths
Enter a fade-in duration in seconds for the start and a fade-out duration for the end. Either can be zero if you only want one.
Apply and download
Export the file with the fades baked in and download it.
Why add fades at all?
Two reasons, one aesthetic and one technical. Aesthetically, a hard cut to full volume feels jarring and an abrupt stop feels unfinished — a fade eases the listener in and out. Technically, when you trim or split audio the cut can land partway through a waveform cycle, leaving a sudden jump from a non-zero value to silence; your speakers reproduce that jump as an audible click or pop. A fade of even a few milliseconds ramps that edge smoothly to zero and the click vanishes.
Fades matter most exactly where audio meets silence, which is why they are the natural partner to any cut. Every time you trim, split or extract a clip you create two fresh edges, and each one is a candidate for a click. Baking in even a near-instant fade at those edges is cheap insurance: it costs a few milliseconds of ramp no listener will ever register as a fade, only as a clean, pop-free start and finish.
How long should a fade be?
It depends entirely on intent, which is why the length is yours to set:
| Length | Effect | Use for |
|---|---|---|
| 5–20 ms | Inaudible as a fade | Killing clicks at a cut point |
| 0.25–0.5 s | A soft, quick ease | Speech, podcast tops and tails |
| 1–3 s | A clear, musical fade | Song intros and endings |
| 5 s+ | A long, cinematic dissolve | Ambient and film transitions |
One thing a fade cannot do is rescue a bad edit point. If a fade-out has to run long just to hide an abrupt musical phrase, the real fix is to move the cut to a more natural boundary first and then add a short fade for polish. Length is for taste and drama — a slow cinematic dissolve, a snappy pop ending — not for papering over the wrong in or out point.
When are fades the right fix?
- Smoothing the start and end of a song so it does not slam in or cut off.
- Removing the click left after trimming or splitting a file.
- Tucking the end of a podcast under an outro so it does not stop dead.
- Building a crossfade feel by fading one clip out and the next in where they meet.
Are fades applied without uploading my file?
Yes — the fades are computed and rendered by ffmpeg.wasm in your browser. Your audio is read, the volume envelope is applied, and the result is offered as a download, all locally with no server involved. Watch DevTools → Network while you apply a fade: nothing is uploaded. Private and unreleased audio stays on your device.
Related audio and video tools
Fades pair naturally with cutting: trim audio or split audio first, then fade the new edges to remove clicks. To set the overall level, use adjust audio volume or normalize audio. And if the track is inside a movie, extract the audio from the video, fade it here, and drop it back.
Your files never leave your device
Processed locally in your browser — nothing is uploaded. You can verify it yourself: open your browser’s developer tools, watch the Network tab, and use the tool — no upload request is ever made.
Frequently asked questions
How do I stop the click at the start of my clip?
Add a very short fade-in — even 5–20 ms. It ramps the abrupt waveform edge smoothly to zero, which removes the click without being audible as a fade.
What is a good fade length for a song?
A 1–3 second fade sounds natural for a musical intro or ending. Shorter feels abrupt; much longer becomes a slow cinematic dissolve.
Can I fade only the end and not the start?
Yes. Set the fade-in to zero and give the fade-out a length, or vice versa. Each is independent.
Why do abrupt cuts pop?
A cut can land partway through a waveform, leaving a sudden jump to silence. Speakers reproduce that discontinuity as a click. A brief fade smooths it away.
Does the fade change the rest of the audio?
No. Only the start and end regions you specify are affected. The middle plays at full level, unchanged.
What curve does the fade use?
A gentle equal-power (logarithmic) curve that matches how the ear perceives loudness, so the fade sounds smooth end to end.
Is my file uploaded?
No. Fades are rendered locally in your browser via WebAssembly. You can confirm no upload happens in the Network tab.