How to Split Video into Segments with FFmpeg (CLI + API)

This article explains how to split a video into equal-length segments using FFmpeg's segment muxer, detailing key flags like `-segment_time`, `-reset_timestamps`, and `-c copy` for fast, keyframe-aligned cuts. It also covers advanced options such as generating CSV segment lists, timestamp-based filenames, and forcing exact timing through re-encoding. Finally, the guide introduces the FFmpeg Micro API as an alternative to managing server infrastructure for automated video processing pipelines.

Originally published at ffmpeg-micro.com https://www.ffmpeg-micro.com/blog/ffmpeg-split-video-into-segments . You need to chop a long video into equal-length clips. Maybe you're building a social media repurposing pipeline, batch-processing uploads for a CMS, or splitting recordings into chapters. FFmpeg's segment muxer handles this, but getting it right means fighting with keyframe alignment, timestamp resets, and infrastructure you don't want to manage. This guide covers the exact FFmpeg commands for splitting video, the flags that matter, and how to skip the server setup entirely with an API. Quick answer Split a video into 10-second segments with no re-encoding: ffmpeg -i input.mp4 -c copy -f segment -segment time 10 -reset timestamps 1 segment %03d.mp4 This uses the segment muxer to cut at the nearest keyframe boundary. Each output file gets its own timestamps starting at zero. How the FFmpeg segment muxer works The segment muxer -f segment tells FFmpeg to write output to multiple files instead of one. It splits based on a time interval you set with -segment time . ffmpeg -i input.mp4 \ -c copy \ -f segment \ -segment time 30 \ -reset timestamps 1 \ output %03d.mp4 Key flags: - -f segment activates the segment muxer - -segment time 30 sets the target duration for each segment in seconds - -reset timestamps 1 resets timestamps to zero for each segment without this, players show wrong seek positions - -c copy copies streams without re-encoding fast, but cuts only at keyframes - output %03d.mp4 is the numbered output pattern 000 , 001 , 002 , ... The %03d pattern in the output filename is required. FFmpeg increments the number for each new segment. Getting a segment manifest If your pipeline needs to know what segments were created and their exact timestamps, add -segment list : ffmpeg -i input.mp4 \ -c copy \ -f segment \ -segment time 30 \ -reset timestamps 1 \ -segment list segments.csv \ -segment list type csv \ segment %03d.mp4 The CSV output looks like this: segment 000.mp4,0.000000,30.030000 segment 001.mp4,30.030000,60.060000 segment 002.mp4,60.060000,85.418750 Each row has the filename, start time in seconds, and end time in seconds. You can also use -segment list type flat for just filenames or -segment list type ffconcat for FFmpeg concat demuxer format. Timestamp-based filenames with strftime For automation pipelines where you're processing videos on a schedule, timestamp-based filenames prevent collisions: ffmpeg -i input.mp4 \ -c copy \ -f segment \ -segment time 30 \ -reset timestamps 1 \ -strftime 1 \ "clip %Y%m%d %H%M%S.mp4" This produces files like clip 20260523 143000.mp4 . Useful when you're processing multiple source videos into the same output directory. The keyframe problem When you use -c copy stream copy, no re-encoding , FFmpeg can only cut at keyframe boundaries. If your video has keyframes every 2 seconds and you request 5-second segments, your actual segments might be 4 or 6 seconds long. Two ways to handle this: Accept keyframe-aligned cuts fast, slightly imprecise : ffmpeg -i input.mp4 -c copy -f segment -segment time 5 -reset timestamps 1 output %03d.mp4 Force exact timing requires re-encoding, 10-50x slower : ffmpeg -i input.mp4 \ -c:v libx264 -crf 23 \ -force key frames "expr:gte t,n forced 5 " \ -f segment \ -segment time 5 \ -reset timestamps 1 \ output %03d.mp4 The second approach re-encodes the video and inserts keyframes at exact 5-second intervals. Accurate, but dramatically slower depending on your hardware and encoding settings. For most batch processing and content repurposing workflows, keyframe-aligned cuts are good enough. Splitting video with the FFmpeg Micro API Running FFmpeg on your own server means managing binaries, scaling for concurrent jobs, and handling timeouts on long videos. The FFmpeg Micro API handles the infrastructure so you can focus on your pipeline logic. The API uses -ss seek and -t duration per transcode job, which gives you precise control over exactly what you extract from each video. Extract a 30-second segment starting at 1 minute: curl -X POST https://api.ffmpeg-micro.com/v1/transcodes \ -H "Authorization: Bearer YOUR API KEY" \ -H "Content-Type: application/json" \ -d '{ "inputs": {"url": "https://storage.example.com/video.mp4"} , "outputFormat": "mp4", "options": {"option": "-ss", "argument": "60"}, {"option": "-t", "argument": "30"}, {"option": "-c", "argument": "copy"} }' The response includes a job ID you can poll: { "id": "b5f5a9c0-9e33-4e77-8a5b-6a0c2cd9c0b3", "status": "queued", "output format": "mp4" } Check status and download the result: curl https://api.ffmpeg-micro.com/v1/transcodes/JOB ID \ -H "Authorization: Bearer YOUR API KEY" curl https://api.ffmpeg-micro.com/v1/transcodes/JOB ID/download \ -H "Authorization: Bearer YOUR API KEY" Split a 5-minute video into 30-second segments programmatically: python import requests API KEY = "YOUR API KEY" BASE = "https://api.ffmpeg-micro.com/v1" VIDEO URL = "https://storage.example.com/video.mp4" SEGMENT SECONDS = 30 TOTAL SECONDS = 300 headers = { "Authorization": f"Bearer {API KEY}", "Content-Type": "application/json" } jobs = for start in range 0, TOTAL SECONDS, SEGMENT SECONDS : resp = requests.post f"{BASE}/transcodes", headers=headers, json={ "inputs": {"url": VIDEO URL} , "outputFormat": "mp4", "options": {"option": "-ss", "argument": str start }, {"option": "-t", "argument": str SEGMENT SECONDS }, {"option": "-c", "argument": "copy"} } job = resp.json jobs.append job print f"Segment {start}s-{start + SEGMENT SECONDS}s: {job 'id' }" All 10 jobs run in parallel on cloud infrastructure. No server, no queue management, no timeout handling on your end. Get a free API key https://www.ffmpeg-micro.com and try splitting your first video. Common pitfalls when splitting video Forgetting -reset timestamps 1. Without this flag, each segment keeps the timestamps from the original video. Players show the wrong position on the seek bar, and some players won't play the segments at all. Audio sync drift with -c copy. Stream copy can sometimes drift audio out of sync at cut points. If you hear pops or sync issues, switch to -c:a aac to re-encode just the audio track while keeping video as copy. Output pattern without %d. If you forget the number pattern in the output filename, FFmpeg overwrites the same file for every segment. Always include %03d or similar. Segment time vs. actual duration. With -c copy , segments won't be exactly the duration you requested. They'll be close, but keyframe alignment means they might vary by 1-2 seconds. If you need frame-accurate cuts, you have to re-encode. Large video timeouts. Running the segment muxer locally on a 2-hour video is fine. Running it on a server with a 30-second HTTP timeout kills the job mid-split. If you're processing long videos in a web pipeline, use an async API or background worker. FAQ How do I split a video into equal parts with FFmpeg? Use the segment muxer: ffmpeg -i input.mp4 -c copy -f segment -segment time 60 -reset timestamps 1 part %03d.mp4 . Replace 60 with your desired segment length in seconds. Segments will be approximately equal, with variation depending on keyframe positions. Can I split video without re-encoding? Yes. Use -c copy with the segment muxer for near-instant splitting. The tradeoff is that cuts happen at keyframe boundaries, so segment durations won't be frame-accurate. For most batch processing and content repurposing workflows, keyframe-aligned cuts are close enough. What's the difference between the segment muxer and using -ss with -t? The segment muxer -f segment automatically splits into multiple files in a single FFmpeg pass. The -ss / -t approach extracts one specific clip per command. The segment muxer is faster for creating many segments from one video locally. The -ss / -t approach works better with APIs and cloud pipelines where each segment runs as an independent job. Does the FFmpeg segment muxer work with audio files? Yes. Same syntax with audio containers: ffmpeg -i podcast.mp3 -c copy -f segment -segment time 600 chunk %03d.mp3 . This splits a podcast into 10-minute chunks without re-encoding. How do I split video into segments with an API? FFmpeg Micro lets you submit transcode jobs via HTTP with -ss and -t options to extract specific segments. Each job runs on cloud infrastructure with automatic scaling. Sign up for a free API key https://www.ffmpeg-micro.com and POST to /v1/transcodes with your input URL, output format, and seek/duration options. Last verified: May 2026 with FFmpeg 7.x and FFmpeg Micro API v1