Frame Rate Comparison
Five lanes move on 30, 60, 120, 144 and 240 clocks. Your screen can paint only so many times a second, so lanes above that ceiling look almost the same.
Rate — fps
Rate — Hz
Per Frame —
Per Sec 960
Each lane jumps on its own clock. When the screen refreshes slower, the higher lanes collapse into the same paint, so they do not get smoother.
What the lanes are doing
The lanes travel the same distance on different clocks. The 30 lane steps about every 33 milliseconds, 60 about every 17, and 144 about every 7. The browser cannot present more pictures than the screen is refreshing. On a 60Hz screen, 120, 144 and 240 usually stick together. On a 144Hz screen, 30, 60, 120 and 144 can still separate, while 240 often matches 144. The animation is not broken. The screen has no extra paint slots.
Frame rate and refresh rate are different numbers
Frame rate is how many new pictures arrive each second. Refresh rate is how many times the screen can swap. Refresh rate is the ceiling. Frame rate is the supply. A 144Hz screen with only 60 new pictures repeats frames, so motion will not look much smoother than 60Hz. Pictures above the refresh rate are dropped. A 24-frame film stays 24 new pictures. The desktop and the pointer are what use the extra refreshes.
How to tell whether the screen is keeping up
First see whether 30 and 60 look different. If those two match, the tab may be in the background or the browser is starving this page. Try fullscreen. If 60 and 120 separate, the output is above 60Hz. If 144 and 240 do not separate and the panel is rated 144Hz, that is expected. If the panel is rated 240Hz and those two lanes still match, check whether the system output is capped at 144Hz or below. For a single hertz number, open the refresh rate test.
Questions
Why do the faster lanes look the same?
Those clocks are already above the screen refresh. The browser paints once per refresh, so the extra steps never appear and the lanes stick together.
30 and 60 look the same. Is that normal?
No. Those two should separate even on a 60Hz screen. Keep this tab in front and try fullscreen. If they still match, the browser is likely starving this page.
How different are 144 and 240?
They can separate only when the screen itself refreshes above 144Hz. On a 144Hz screen they should look almost the same. Whether you can split them matters more than the label.
Films are 24 frames. Does a high refresh rate still help?
The film stays at those frames. A high refresh rate makes the desktop, menus, and pointer smoother. It does not turn a 24-frame film into 240 new pictures. Motion smoothing in a player is a separate feature.
If the game cannot produce more frames, does a faster screen help?
The screen can show only frames that already exist. A game locked at 60 frames still looks near 60 on a 144Hz screen. The desktop and the pointer get smoother. The game does not.
How do the lanes move?
One animation loop steps each lane on its own interval, and the motion is a transform, not a layout change. The 30 lane jumps sparsely and the 144 lane jumps finely, but you only see the steps the screen can refresh.