Display & Frame Rate Tester
Check the display information your browser reports, then measure animation frame delivery over a short test. Use the results to compare browser conditions and frame pacing.
Reported display information
Browser zoom, operating-system scaling, multiple monitors and privacy settings can change these readings. Estimated device pixels are CSS dimensions × device pixel ratio; they do not confirm your panel's native resolution.
Browser animation frame test
Keep this tab visible. The first 0.75 seconds are warm-up. requestAnimationFrame measures browser callback delivery, not an independently verified monitor refresh rate, input latency or game performance.
How to use Display & Frame Rate Tester
- Read the reported screen size and viewport. Move the browser between monitors or resize it to compare the readings.
- Choose a duration and press Start frame test. Keep this tab visible and let the animation run.
- Compare average FPS with median and 95th-percentile intervals. Download the JSON report to keep the measured values.
Method and limits
The frame test records requestAnimationFrame timestamps after a short warm-up. Average FPS is the number of measured intervals divided by their total duration. Median describes a typical interval; the 95th percentile highlights slower intervals. The test stops when the tab is hidden. Power-saving, other applications, browser limits and display synchronization can all affect the result.
Reference: MDN animation frame timing, MDN reported screen width
Frequently asked questions
Is browser FPS the same as my monitor refresh rate?
Not necessarily. Browser animation callbacks are often synchronized with display refresh, but throttling, rendering load, power-saving and variable refresh can alter their delivery.
Why does my screen size differ from the advertised resolution?
Browser screen dimensions are usually CSS pixels. OS scaling, browser zoom, display selection and privacy settings affect the reported values.
Does this measure hardware input delay or gaming FPS?
No. It measures this page’s animation callbacks. It cannot directly measure physical panel response, keyboard latency or the frame rate of another application.
Examples and practical checks
Understand the result before using it elsewhere.
- Explore TestingCompare tools and their limits
- How we test these toolsMethods, verification and limitations