Change a Video's Frame Rate
Pick a video and a target fps — frames are dropped or duplicated in your browser, nothing is uploaded.
About this tool
Change how many frames per second a video plays at — without leaving your browser. Pick a video, type a target frame rate (say 30), and the clip is re-timed locally. The file never leaves your device.
How it works
The tool runs ffmpeg's fps
video filter, compiled to WebAssembly. When you lower the frame rate (e.g.
60 → 30 fps) it drops the extra frames; when you raise it (e.g. 24 → 60 fps)
it duplicates frames to fill the gaps. Either way the clip's duration stays
the same — only the number of frames per second changes.
Because the frame timing changes, the video stream is re-encoded to H.264
at -crf 20 (visually near-transparent quality). The audio track is left as-is
and copied across untouched. An .mp4, .mov, .m4v, or .mkv keeps its
container; other inputs (.webm, .ogv, .avi, …) come out as MP4 (and
their audio is re-encoded to AAC), since those containers can't hold H.264/AAC.
Example
Upload a 60 fps screen recording, set the target to 30, and you get the same clip at half the frame rate — smaller and smoother on players that struggle with 60 fps, with identical length and audio.
Notes
- Duration is preserved. This changes frames-per-second, not playback speed. To make a clip play faster/slower, use a speed tool instead.
- Frame drop/duplication, not interpolation. Raising the fps repeats existing frames; it does not synthesise new in-between frames (no motion interpolation).
- Private by design. Everything runs in your browser. No upload, no server.
- The target fps is clamped to the 1–240 range.
FAQ
Does changing the frame rate make my video play faster or slower?
No. The clip keeps its original duration. Lowering the fps drops frames and raising it duplicates frames, but a 10-second clip stays 10 seconds long. If you want the video to actually play faster or slower, that's a speed change, not a frame-rate change.
What fps should I pick?
Common targets are 30 (web/general), 24 (a cinematic "film look"), 25 (PAL / European broadcast), and 60 (smooth motion / gaming). The default is 30. Any value from 1 to 240 is accepted and clamped into that range.
Can I get smooth slow motion by raising the fps?
Not from this tool. Raising the frame rate duplicates existing frames rather than generating new in-between ones, so it won't look smoother than the source — true smoothness needs motion interpolation, which this doesn't do.
Do the codecs or file format change?
The video is always re-encoded to H.264 (needed because the frame timing
changes). An .mp4, .mov, .m4v, or .mkv keeps its container and its audio
is copied through untouched; anything else (.webm, .ogv, .avi, …) is
converted to MP4 with its audio re-encoded to AAC, because those containers
can't hold H.264/AAC.
Why does it take a while on longer clips?
The whole re-encode runs on your own CPU via ffmpeg compiled to WebAssembly — that's what keeps the video on your device. Encoding time grows with duration and resolution, so a long 4K clip can take several minutes where a short phone clip finishes in seconds.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool video-fps 'url=https://example.com/input' 'fps=30'New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/video-fps/?url=https://example.com/input&fps=30Machine-readable descriptor: tool.json — title + parameters JSON Schema for agents.