Fade an Audio File In and Out

Fade audio in and out, in your browser

Pick an audio file and how many seconds each fade should last — the fades are applied with ffmpeg, entirely in your browser. The default 3 seconds each way gives a gentle, radio-style open and close; set either side to 0 to fade only the other one. Fades fix abrupt starts, clipped endings, and the click you often hear when a track was cut mid-waveform.

Worked example

A clip trimmed out of a longer recording starts and stops dead: upload clip.mp3 and leave both fields at 3 — the result clip-fade.mp3 opens smoothly and dies away naturally. For a ringtone, try Fade-in 0.5 and Fade-out 1: quick enough to keep the hook, soft enough to lose the click. For a podcast outro over music, a long Fade-out of 8–10 works well.

Picking fade lengths

• 0.3–1 s — removes clicks and abrupt edges without being audible as a "fade"; right for ringtones and sound effects.
• 2–4 s — the classic musical fade; the default 3 s sits here.
• 5–15 s — long DJ-style outros, background-music beds under speech.

Limits and edge cases

• Input files up to 10 MiB; any format ffmpeg can decode works.
• Each fade can be 0–30 seconds; values outside that range are rejected.
• Both fades at 0 is rejected — there'd be nothing to do.
• A fade longer than the track simply fades across the whole file; if fade-in and fade-out together exceed the length, they overlap and the middle never reaches full volume.
• The fade curve is ffmpeg's default (triangular/linear gain ramp).
• Output is re-encoded (mp3/ogg at 192 kbps; wav/flac lossless; m4a AAC). Embedded album art is dropped.

FAQ