What frame rate means
Frame rate, written as FPS for frames per second, is how many still pictures a video shows each second. Cinema traditionally uses 24, many screens and web clips use 30, and some phones and games record at 60. A higher number gives smoother motion and also means more frames to store.
Changing the frame rate tells the encoder to produce a different number of frames per second. Going from 60 to 30 keeps every second frame, so a 10 second clip drops from 600 frames to 300. Going the other way, from 24 to 30, repeats some frames to fill the gap. Repeating frames makes the count higher but does not create real new motion, so it will not look smoother.
The video is encoded again after the change, so the tool processes every frame and takes a while on long clips.
When you would change it
A common reason is to make footage from different sources match, for example mixing a 24 FPS camera clip with a 30 FPS screen recording before joining them. Matching the rate avoids stutter or errors in tools that expect the same rate throughout.
Lowering the rate is also a simple way to reduce work for a device and shrink a file, since fewer frames are stored. A 60 FPS clip converted to 30 FPS holds half as many frames. This suits talking-head footage or screen recordings, but fast action may look less smooth.
If the file size is your main goal, the Video Compressor is built around a quality setting, and the Change Resolution tool reduces the pixel count instead.
How to change the frame rate with this tool
- Drop a video file onto the upload area, or click it to choose one.
- In the Target FPS box, type the frame rate you want. The box starts at 24.
- Click Run. On first use the video engine downloads (roughly 30MB) and is cached.
- Wait for the progress bar to finish, then watch the preview.
- Click Download. The file is saved as your original name followed by
-change-fps, as an MP4.
There are no preset buttons, so you choose any number you type. The tool applies that target rate to the whole video.
Tips and limits
Pick a rate that suits the content. Dropping a fast-moving clip to a low rate makes it look choppy, and raising a low-rate clip will not smooth it, because the new frames are copies of existing ones.
The tool does not validate the value. A zero, negative or blank entry is likely to make the job fail, so keep the number positive. Very high rates create more frames than the content needs and a heavier file.
Only the frame rate is changed here. The resolution stays as it was, although the file is re-encoded with default settings and there is no quality control. Output is always an MP4.
Since processing happens in your browser, long or high-resolution videos can be slow and may run out of memory, which produces an error message. A shorter test clip is a good way to check the result before committing to a long file. Starting from the original file each time avoids piling up quality loss from repeated encodes.