Fade In / Fade Out Audio

What a fade does to a sound

A fade changes loudness over time. In a fade in, the volume starts at silence and climbs to the normal level over a few seconds. In a fade out it does the reverse: the normal level slides down until nothing is left. Between the two, the audio plays untouched.

That sounds like a tiny detail, yet it decides whether a clip feels finished. A recording cut from the middle of a song begins with a jolt and stops with a thud. Add a two-second fade in and a four-second fade out and the same clip starts to breathe like a complete piece. Podcasts, video intros, phone-recorded clips, loop-based beats and ringtones all benefit.

The fade in and the fade out are separate settings. Fade in runs from 0 to 15 seconds and defaults to 2. Fade out runs from 0 to 20 seconds and defaults to 4. Set either one to zero to apply only the other, for example when a track already begins cleanly and you only need an ending.

Fade in and fade out: the difference in practice

People often ask whether the two are different tools. They are the same operation pointed in opposite directions. A fade in is for the front of the file and a fade out for the back. The reason to treat them apart is that they serve different goals, so they want different lengths.

A fade in is mostly about politeness: it prevents the ear from being startled and hides a click at the first sample. One to three seconds is usually plenty, and some material needs only a tenth of a second, the smallest step on the knob. A fade out is about closure: it tells the listener that the piece is ending on purpose. Because endings carry more weight, they tend to be longer, from three seconds for a short clip to ten or more for a radio-style outro.

Fades are also not the same thing as a crossfade. A crossfade overlaps the end of one track with the start of the next. This tool treats one file at a time, so it does not make crossfades; the audio joiner does, with an equal-power overlap of up to 8 seconds between files.

The three curves

The table in the Numbers tab lists the loudness at points through a fade in, for each curve. A fade out is the same picture reversed. The choice of curve changes how the fade feels even when the length is identical, because our ears do not hear loudness in a straight line.

Linear raises the amplitude evenly, from 0 to 100 percent. It is the simplest and the easiest to reason about, but it is rarely the smoothest to hear. Halfway through, the signal is at 50 percent of full amplitude, which is only about 6 dB below the top. The ear hears most of the change in the first part of a fade in and the last part of a fade out, so a linear fade can seem to jump in early and then crawl.

Equal power follows a quarter of a sine wave. It rises quickly at first and levels out near the end. Its name comes from the fact that two such curves played in opposite directions keep the combined power steady, which is what you want in a crossfade. For a single fade it sounds smooth and natural, and this is the curve to start with when you have no strong preference; the tool opens on Linear, so pick it from the Curve menu.

Logarithmic is even in decibels. It starts at minus 60 dB, which is effectively silence, and climbs in a straight line on a decibel scale. Because loudness perception is roughly logarithmic, the result sounds like a steady, even swell. In amplitude terms nearly all the change happens near the end of a fade in, so the first part of a long log fade in is very quiet before the sound arrives. For fade outs it gives the classic long tail that disappears slowly into the noise floor.

Presets and how long to make a fade

Three presets give you starting points. Short is for tidying a clip: a brief fade at each end that removes the harshness of a hard cut. Song suits a full track and gives a gentle intro and a gradual outro. Radio ending stretches the last part so a loop or a clip dissolves the way a song does on air.

Concrete lengths help. To remove a click only, you need a fraction of a second, which is why the Short preset exists. For a song intro, 1 to 4 seconds works. For a voice-over, 0.5 to 1 second feels natural. For a radio-style ending, aim for 4 to 10 seconds, longer if the outro is a repeating groove.

The right length also depends on the audio underneath. A fade that is longer than the part of the clip that stays at full level leaves nothing to hear. If your file is 20 seconds long, a 15-second fade in plus a 20-second fade out overlaps itself and the clip never reaches full volume. Keep the two fades together under the file length with room to spare.

Common uses with settings to try

For a video intro of 10 seconds, try a fade in of 1 second and a fade out of 2 seconds with the equal power curve. For background music under speech, use a fade in of 2 to 3 seconds so the music does not compete with the first words, and a fade out of 4 to 6 seconds at the end.

For a looped beat that must stop, pick the logarithmic curve with a fade out of 8 seconds or more. The slow decay in the quiet end is the part that sounds finished. For a ringtone, a fade in of 0.2 seconds and a fade out of 1 to 2 seconds keep it from stopping with a snap.

For a field recording or a long ambient clip, a long fade in of 8 to 12 seconds makes the room appear gradually, as if you were walking in. Use the linear curve there if you like the steady, mechanical feel, or the logarithmic curve for something closer to a natural emergence.

Order of operations

Fades belong near the end of the chain. If you add a fade and then trim the file, the trimmer may cut the faded part away. If you boost volume after the fade, nothing breaks, but a limiter or boost applied later can raise the quiet tail more than you planned, because raising the level lifts the near-silent parts too.

A good routine is to trim first, adjust loudness second, apply effects like reverb third, and fade last. The links under the tool, labelled Continue with the result in, hand the processed audio to the next page without any upload step, so you can move from the trimmer into this page and afterwards on to the joiner. The studio on the home page has a Fade module too, which always uses the equal power curve; this page is the one with a choice of curves.

If you intend to join several faded pieces, remember that two fades meeting at a join leave a dip in the middle. In that case do not fade the inner ends at all; leave them alone, apply the fades only to the very beginning and the very end, and use the joiner's crossfade for the seams.

Formats and file size

A fade does not change the length of the file, only the loudness inside it. The saved size depends on the format you choose, either an MP3 bitrate or a WAV bit depth, and a figure appears ahead of the download so that you can take the smallest option that still sounds right. If your source is a video, the sound of most MP4, MOV and WebM files opens here, and the faded result is saved as MP3 or WAV.

For a final file to publish, a 192 or 256 kbps MP3 is a balanced pick. If more editing comes next, save WAV so another round of lossy encoding is not stacked onto the first one. Files up to 250 MB can be opened, and the preview responds within about a quarter of a second after you turn a knob.

Processing happens on your device, and the audio is never sent away. Your latest file is kept in this browser's storage on this device so other tools can offer it; clearing site data removes it. Work with audio you own or may use, because this page does not fetch anything from streaming services.

Questions about streaming app crossfade

Many music apps include a crossfade option in their playback settings, which blends the end of a song into the start of the next one while you listen. That is a feature of the player, applied as the audio plays, and it does not alter any file. WaveTinker is not connected to any streaming app and does not change what those apps do.

If you want the same blend baked permanently into a file, join the two tracks with the audio joiner and choose a crossfade. You get one new file with the overlap built in, and it will sound the same on any device.