FFmpeg Cookbook
JA

Fade In / Fade Out Tool

Add a fade-in at the start and a fade-out at the end of your video. Black or white fades, with optional audio fade (afade).

Your file is not uploaded
Drag & drop a video, or tap to select
MP4 / MOV / WebM, up to 500 MB
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The fade-out start position is calculated automatically from the video duration. Video is re-encoded with H.264 (CRF 23).
Processing… 0%

Equivalent FFmpeg command

CLI command for your current settings. Updates live as you change controls.

ffmpeg -i input.mp4 -vf "fade=t=in:st=0:d=1:c=black,fade=t=out:st=9.000:d=1:c=black,scale=trunc(iw/2)*2:trunc(ih/2)*2" -c:v libx264 -preset fast -crf 23 -pix_fmt yuv420p -af "afade=t=in:st=0:d=1,afade=t=out:st=9.000:d=1" -c:a aac -b:a 128k -movflags +faststart output.mp4

What to do next

Command Reference
Related Tools
Video Merger Add BGM Tool

How to use

  1. Drop the videoDrag and drop an MP4, MOV, WebM or similar file, up to 500 MB. The video duration is read automatically.
  2. Set the fadesChoose fade-in / fade-out lengths (none / 0.5 / 1 / 2 / 3 s; both default to 1 s) and the fade color (black / white). Audio fade is on by default.
  3. RunClick Apply fades. When it finishes, a preview and a download button appear.

Recommended settings

Vlogs / everyday videos
1 s in / 1 s out / black
These are the default settings. Use them if unsure.
Slideshows / memory reels
2 s in / 3 s out / white
Slow white fades give a soft, gentle feel.
Fixing abrupt BGM cutoffs
0.5 s in / 2 s out / audio fade ON
The music tapers off at the end, so a mid-song ending still sounds intentional.

When it goes wrong

Fade-out starts slightly off-position

Cause: The start is calculated from the duration the browser reads, and in some videos that differs slightly from where the picture ends.

Fix: Pick the next longer fade-out.

Audio fade has no effect

Cause: The video has no audio.

Fix: Then only the picture gets the fade.

File size changed after processing

Cause: A fade changes the picture itself, so it must be re-encoded: the video with H.264 (CRF 23) and the audio with AAC at 128 kbps.

Fix: This cannot be avoided when adding fades. To make the file smaller, compress it afterwards.

Questions

Can I apply only a fade-in, or only a fade-out?

Yes. Set the side you don't need to "None". If both are "None", the run button is disabled.

What happens with very short videos?

If the fade-out is longer than the video, it starts at 0 and the whole clip fades out. If the video is longer than the fade-in and fade-out together, the two do not overlap (6 seconds or more for 3 s each).

Does quality drop?

A little. A fade changes the picture, so the video is re-encoded with H.264 at CRF 23, the default setting of libx264. The audio is converted to AAC at 128 kbps too.

I want to crossfade between two clips

This tool fades a single video at its start and end. For crossfade joins between multiple clips, use the Transition option in the Video Merger.

Should I add BGM before or after fading?

Add music first with the BGM tool, then run this tool with the audio fade on; the picture and the music fade out together.

More detail (settings, limits, FFmpeg commands)

What each setting means

Fade-in length
How long the picture takes to emerge from black (or white) at the start. Set to "None" to skip.
Fade-out length
How long the picture takes to dissolve into black (or white) at the end. Start position = duration − fade-out length, computed automatically.
Fade color
Base color of the fade. Black is the standard; white suits bright vlogs and slideshows.
Audio fade
When checked, afade is applied with the same lengths so the audio ramps up and out smoothly with the picture.

Browsers and limits

  • Maximum file size: 500 MB
  • Output is MP4: the video is re-encoded with H.264 (CRF 23) and the audio with AAC at 128 kbps (a fade cannot be added by stream copy)
  • Files whose duration cannot be read are rejected (required to position the fade-out)
  • Fade lengths are 0.5, 1, 2 or 3 s; use desktop FFmpeg for other values

The same job with the FFmpeg command line

1 s in + 1 s out (60-second video, black)
ffmpeg -i input.mp4 -vf "fade=t=in:st=0:d=1,fade=t=out:st=59:d=1" -af "afade=t=in:st=0:d=1,afade=t=out:st=59:d=1" -c:v libx264 -preset fast -crf 23 -pix_fmt yuv420p -c:a aac -b:a 128k -movflags +faststart output.mp4
st = duration − fade-out length. This tool computes it for you.
White fade (slideshow style, 60-second video)
ffmpeg -i input.mp4 -vf "fade=t=in:st=0:d=2:c=white,fade=t=out:st=57:d=3:c=white" -c:v libx264 -crf 23 -pix_fmt yuv420p -c:a copy output.mp4
c=white gives a white fade. -c:a copy keeps the audio as is (the tool converts the audio to AAC).
Fade-out only, audio included (60-second video)
ffmpeg -i input.mp4 -vf "fade=t=out:st=58:d=2" -af "afade=t=out:st=58:d=2" -c:v libx264 -crf 23 -pix_fmt yuv420p -c:a aac -b:a 128k output.mp4

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