Fade In / Out
Fade Audio adds a smooth fade-in at the start and fade-out at the end of a track, so it eases in and out instead of starting or stopping abruptly. Set each fade's length and export a more polished clip, processed entirely in your browser.
Add your audio file
The file is read by your browser and stays on your device — there is no upload step.
Your audio
The work runs in this tab. Nothing is sent anywhere, and the download is generated locally.
Output —Load audio
How to use Fade In / Out
- 01Upload
Add your audio
Drop your file in; its length is detected for placing the fades.
- 02Customize
Set the fades
Choose how many seconds the fade-in and fade-out should each last.
- 03Process
Download
Export to apply the fades and save the smoothed track.
What a fade is for
An abrupt start or stop mid-waveform clicks. A fade of even a few milliseconds removes the discontinuity entirely and is inaudible as a fade.
A longer fade is a musical decision rather than a technical one — it ends a piece that has no natural ending.
How long
- De-clicking5–20 ms
Long enough to remove the step in the waveform, short enough that nobody perceives a fade at all.
- Speech in and out0.2–0.5 s
Reads as a clean start rather than a fade. Anything longer sounds like the speaker walked towards the microphone.
- Music ending3–8 s
Long enough to feel deliberate. Under two seconds usually reads as running out of tape.
Signs it is wrong
The first word is swallowed — A fade-in longer than the gap before speech eats the start of it. Trim the silence first, then fade.
It sounds like a mistake, not a choice — A one-second music fade tends to read as an error. Either commit to a longer fade or cut cleanly.
There is still a click — Then the click is not at the edge — it is at an internal edit point, and needs a fade there instead.
This is baked into the export
The fade is written into the samples. Removing it later means raising the faded section, which raises the noise with it.
Fade lengths are a matter of taste and often need a second attempt. Work from the source each time.
Supported formats
- MP3
- WAV
- M4A
- OGG
- FLAC
- Maximum file size —
- bounded by your device's memory
- Processed by —
- FFmpeg (WebAssembly), on your device
Your file, and what the page does
Your file is never uploaded. Fade In / Out reads it into this browser tab and processes it with FFmpeg compiled to WebAssembly on your own device. There is no upload endpoint in the application and no copy on any server — closing the tab discards it.
That is also why processing takes longer here than on a site that uploads: your device is doing the work rather than a rack of servers. The trade is that the file never leaves it.
What the page does send or fetch
- The processing engine, once
- The first time you use any video or audio tool, the browser downloads the FFmpeg WebAssembly build (~30MB) from the jsDelivr CDN and reuses the cached copy afterwards. That is a file coming to you — no part of your own file is in the request.
- Ads on the page
- The site is funded by advertising, so the page loads Google AdSense. That carries the usual web basics — IP address, browser, referring page — as on any ad-supported site.
- An anonymous usage counter
- When Fade In / Out finishes we record that the tool ran, whether it succeeded and how long it took. No file data, no identifier, no cookie.
Your file is not on that list. How this works.
Frequently asked questions
Yes — set one fade to zero seconds to apply just the other.
One to three seconds suits most music; shorter fades work well for speech and effects.
No — the fades are applied within the existing audio, so the duration stays the same.
Yes — Fade In / Out is completely free. There's no account, sign-up, watermark or limit.
No. It runs in any modern browser — Chrome, Edge, Safari, Firefox, Brave — with nothing to download or install.
Not sure a fade is what you need?
- The ends need to be smoothFade In / Out
- There is dead air to remove firstTrim Audio
- The whole thing is too quietNormalize Audio
- The loop join clicksLoop Audio
Edit any media with a right-click
Add Dexta Studio to Chrome and open any image, video, audio or PDF straight into the right tool — free, nothing uploaded.