Fade In / Fade Out
Add fade in and fade out to audio clips for smooth starts and endings.
100% in your browser — files never leave your device
Smooth audio transitions with fade envelopes
Abrupt starts and stops are one of the most noticeable signs of rough audio editing. A fade in ramps the volume from silence at the beginning of the clip; a fade out ramps it back down to silence at the end. Together, they are the standard way to introduce and conclude a music track, podcast segment, or audio bed.
This tool uses FFmpeg's afade filter, applied independently for each end. The fade-in window starts at time 0; the fade-out window is positioned so it ends exactly at the last frame. Both use a linear amplitude ramp. Durations up to half the total clip length can be set for each fade.
Load your audio, play it to confirm timing, set your fade durations, and download the result. Everything runs in your browser with FFmpeg.wasm. No upload needed.
Frequently asked questions
What does a fade in and fade out do?
Fade in gradually raises the volume from silence at the start of the clip. Fade out gradually lowers the volume to silence at the end. Both use a linear ramp. They are commonly used to avoid abrupt starts and stops in music, podcasts, and video backing tracks.
Can I apply only a fade in or only a fade out?
Yes. Set the duration you do not want to 0 seconds to disable it. You can apply a fade in with no fade out, a fade out with no fade in, or both simultaneously.
Is my audio uploaded anywhere?
No. All processing runs in your browser using FFmpeg.wasm — a WebAssembly build of FFmpeg. The WASM binary (about 25 MB) downloads from a CDN on first use and is then cached. Your audio never leaves your device.
Why do I need to know the audio duration?
The fade-out start time is calculated as (total duration - fade-out duration). To compute this accurately, the tool reads the duration from the HTML5 audio element after the file loads. Load a file and wait for the player to appear before adjusting the fade settings.
What happens if the fade in and fade out durations overlap?
The process button is disabled when the combined fade durations exceed the total audio duration. This prevents creating a fade-out that starts before the fade-in ends, which would produce silence in the middle of the clip.