Speed Up or Slow Down Video
Watch tutorials at 2x, slow down a sports clip for analysis, or sync a reaction to lyrics — change speed from 0.5x to 3x with audio in tune.
Change video speed
Sign in to run this tool — 100 free credits on signup.
FFmpeg flags used by this tool
Quick reference for what each parameter actually does.
- setpts=N*PTS
- Multiplies presentation timestamps by N — counter-intuitively, smaller N = faster playback. 2x speed = 0.5*PTS.
- atempo=N
- Changes audio tempo by N without affecting pitch. The voice still sounds like the same person, just faster or slower.
- atempo limits
- atempo only accepts 0.5-100 in a single pass. We chain multiple atempo for extreme values, but 0.5-3x covers nearly every real use case.
How it works
- 01
Upload or paste a URL
Drop a video from your computer, or paste a public URL. Up to 5 GB.
- 02
Pick a speed
0.5x for slow-mo, 1.5x to skim a tutorial faster, 2x for serious fast-forward, 3x for time-lapse vibes.
- 03
Process in the cloud
Video timestamps are scaled and audio is re-tempo'd. Both stay in sync. Audio pitch is preserved.
- 04
Download the result
Temporary download link as soon as it's done. Files auto-delete after 7 days.
FAQ
Will the audio sound chipmunk-y when sped up?
No — we use atempo, which keeps the original pitch. 2x sounds like the same person talking faster, not a chipmunk. (If you actually want the chipmunk effect, that's a different filter.)
Why are there no speeds above 3x in the UI?
atempo's clean range per pass is 0.5-2.0 (we extend with chaining). Beyond 3x the audio starts to sound artifact-y and most use cases — fast-forwarding tutorials, slow-mo — fit comfortably in 0.5-3x. Need 10x time-lapse? Use the API and pass `-an` to drop audio entirely.
Will the file size change?
Faster speed = shorter video = smaller file (it's the same content with fewer total frames written). Slower speed = bigger file. The bitrate per second is roughly the same.
Can I keep frame rate or change it?
We keep source frame rate by default. For 'true' slow-mo from a 60fps source, the smoothness comes from having those extra source frames spread over more output time.
Why does my 0.5x video look choppy?
Because we're stretching frames in time, not interpolating new ones. A 30fps source at 0.5x effectively shows each frame for twice as long. For interpolated buttery slow-mo (like minterpolate), use the API with extra filter args.
Is this free?
Sign up for 100 free credits. A speed change costs 3-8 credits depending on length. No subscription, top up as you go.
Related video tools
Need to change speed in code?
This tool is a wrapper around our REST API — three lines of curl will do the same job in your build pipeline or backend.
View API docscurl -X POST https://api.ffhub.io/v1/tasks \
-H 'Authorization: Bearer YOUR_API_KEY' \
-H 'Content-Type: application/json' \
-d {
"command": "-i https://you.com/in.mp4 -vf \"setpts=0.5*PTS\" -af \"atempo=2\" output.mp4"
}