Split a video into equal-length parts
A long video to share across several messages, ten-minute pieces for a platform with a length limit, regular clips for statuses: ffmpeg splits a video into equal parts with a single command, without creating them one by one.
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How to use it
- Install ffmpeg if you haven't already.
- Open a terminal in the folder containing your file: the parts will be saved there.
- Copy the generated command, adjust the file names if needed, then run it.
- Open the resulting file to check the result.
Fast mode or precise mode?
Fast mode doesn't recompress anything: it's instant and lossless, but the cuts land on keyframes. It's perfect for archiving or splitting movies. Precise mode re-encodes to cut exactly at the second you chose: essential if the parts must meet a strict length or size limit.
A size limit rather than a length limit
If what you really need is a maximum size (for example 25 MB per message), compress the video with the target size page instead, or split by length while estimating the bitrate.
Frequently asked questions
Why aren't all the parts the same length in fast mode?
Without re-encoding, ffmpeg can only cut at keyframes. If the video has one every 10 seconds, the parts last a multiple of 10 seconds, as close as possible to the value you asked for. Precise mode inserts a keyframe exactly at each cut.
What does %03d mean in the output name?
ffmpeg replaces this pattern with a three-digit number: part_000.mp4, part_001.mp4, part_002.mp4… In a Windows .bat file, you need to double the percent sign (%%03d).
Can I split an audio file the same way?
Yes: change the output extension to .mp3 or .m4a, and use only the "-c copy" option.
Where are the parts saved?
In the folder where you run the command, next to the original file.