Frames Per Second

The fps parameter sets the output frame rate, in frames per second. video-fps is an alias and behaves identically.

By default, Imgix preserves the source frame rate. Set fps to a lower value to reduce file size, or to a higher value to raise the frame rate.

Video Output

For video output (such as fm=mp4), fps accepts values up to 120.

• Lower than the source frame rate, at normal playback speed: frames are dropped to reach the target rate. This reduces file size and never uses AI interpolation.
• Higher than the source frame rate: frames are duplicated to reach the target rate. To generate new intermediate frames with AI instead, add video-interpolation=true.
• With video-speed below 1.0: the slowed video is conformed to the target frame rate using AI interpolation. For example, video-speed=0.5&fps=24 produces smooth half-speed playback at 24 fps.

AI interpolation is billed as a Premium operation. Changing the frame rate on its own does not run AI interpolation unless you opt in with video-interpolation=true. See Video Credits for details.

Animated Output

For animated output (fm=gif, or video-generate=animation with WebP, AVIF, or PNG), fps defaults to 15. The maximum is 30, and the output never exceeds the source frame rate. Higher values produce smoother animation and larger files.