Browser FFmpeg recipe

Fade Audio Online with FFmpeg

Create audio with a 2 second fade in and a 2 second fade out.

Command

Run this FFmpeg command

ffmpeg -i input.mp3 -af afade=t=in:st=0:d=2,afade=t=out:st=28:d=2 -b:a 192k faded.mp3

When to use it

  • music clips
  • podcast intros
  • clean endings

How it works

  1. Upload the audio file.
  2. Adjust fade start and duration values.
  3. Run FFmpeg and download the faded audio.

Option reference

OptionWhat it does
afade=t=in:st=0:d=2Fades in from the start over 2 seconds.
afade=t=out:st=28:d=2Fades out starting at 28 seconds.
-b:a 192kSets output MP3 bitrate.

Practical notes

  • Change the fade-out start time to match your audio duration.
  • For video, combine afade with video copy settings.

FAQ

How do I make a longer fade?

Increase the d value, for example d=5 for five seconds.

Can I add only fade in?

Yes. Remove the second afade filter.