Split video into segments

Large video files need to be split in several practical situations. File size limits on platforms (WhatsApp 16 MB, Discord 25 MB, email 10 to 25 MB) prevent sharing a full clip in one attachment. A long recording (a lecture, a meeting, a workshop) becomes more useful when broken into sections that correspond to topics. Video courses are typically distributed as individual lesson files, not one monolithic file.

Splitting also facilitates parallel editing: if multiple people are editing different sections of a long video, splitting into segments first allows independent work without shared timelines.

Each segment is exported in a separate FFmpeg call. The tool calculates the total video duration, divides it by the number of segments you choose, and then runs one export per segment. Each call uses -ss (start position placed before -i for fast seek) and -t (duration) to define the segment boundaries. A -avoid_negative_ts make_zero flag corrects timestamps that can go negative at split points, which would cause some players to misdisplay the start of a segment. Each segment is re-encoded with libx264 at the ultrafast preset, AAC audio at 128 Kbps, and +faststart.

Segments are made available for download one at a time as each FFmpeg call completes, so you do not have to wait for all segments before downloading the first one.

The split points are calculated mathematically from the total duration, not from keyframes. If a split point falls in the middle of a scene, both adjacent segments will re-encode cleanly starting from that point (because re-encoding is used, not stream copy). This is more accurate than stream-copy splits, which must snap to the nearest preceding keyframe.

For content where you want to split at natural boundaries (chapter breaks, scene changes), trim the video to the approximate boundary first using the Trim tool, then split the trimmed clip.

Splitting with FFmpeg on the command line requires running a separate -ss / -t command for each segment, with the total duration calculated manually. Some GUI tools can split but require importing the full video into a project. This tool calculates the segment boundaries, runs each FFmpeg call in sequence, and downloads each part as soon as it is ready, without requiring you to manage the split math or the per-segment commands.