Fade In & Out
Fade In & Out adds a fade-in and fade-out to an audio file in your browser, with smooth or linear curves of up to 30 seconds each and a waveform preview.
At a glance
- Accepts
- MP3, M4A, AAC, WAV, FLAC, OGG and Opus audio, or the sound in a video file
- Outputs
- MP3 (192 kbps), WAV (16-bit) or M4A when the browser has an AAC encoder; the sample rate is kept where the format allows
- Where it runs
- Entirely in your browser, on your device
- What leaves your device
- Nothing - the file never leaves your device
- Limits
- Fades only at the very start and end; each fade at most half the file
- Account
- Not required - there is no sign-up
- Price
- Free, with no watermark and no usage cap
- Made by
- Visrut
- Last updated
- 13 October 2026
Ease a song, ringtone or podcast intro in from silence and let it fade away at the end, instead of starting and stopping abruptly. Set each fade's length, pick a smooth or linear curve, and the waveform shows the shape before you apply it. Nothing is uploaded.
How to use it
- Drop in an audio file.
- Set the fade-in and fade-out lengths, and pick the curve.
- Press Apply fades, listen, and download as MP3, M4A or WAV.
Honest limits
- Fades go at the very start and end of the file. To fade somewhere else, trim the file first.
- Everything runs in your browser tab; the file is never uploaded.
- Long files are read and processed a piece at a time, so the length of the recording isn't the limit. The finished file is held in memory until you save it: about 86 MB per hour as MP3, and about 690 MB per hour of 48 kHz stereo as WAV, which a phone may not manage.
- MP3 and M4A are re-encoded at 192 kbps, which is a lossy step (like any edit to an MP3). WAV is uncompressed 16-bit.
- M4A is offered only when the browser has an AAC encoder (most desktop Chrome, Edge and Safari do; Firefox does not).
Frequently asked questions
What's the difference between smooth and linear?
Linear changes the volume at a steady rate. Smooth follows an S-shaped curve that starts and finishes gently, so you can't hear exactly where the fade begins or ends. Smooth suits most music and voice; linear is there if you need a predictable ramp.
Can I add only a fade-out?
Yes. Set the fade-in to 0 and only the end is faded, or the other way round.
How long can a fade be?
Up to 30 seconds each, and no longer than half the file, so the two fades never overlap.
Can I cut the file shorter first?
Use Trim Audio to cut it, then fade the trimmed file here.
Is my audio uploaded?
No. The fades are applied inside your browser tab.