About this test
Input lag is the time between pressing a button and seeing the result on screen. The browser mode measures how long each click waits for the next frame and adds one and a half frame times for scan-out, which gives a realistic estimate of the system part of the delay. The camera mode measures everything, including the mouse and the monitor's own processing: film the mouse and screen in slow motion, count the frames between the click and the flash, and the calculator converts them to milliseconds.
How to use this test
- In browser mode, click the box at least 20 times at a steady pace and read the estimated total.
- For a true measurement switch to camera mode and set your phone to slow motion (240 fps is ideal).
- Film your finger clicking the mouse with the box in view. The box flashes white on each click.
- Step through the video frame by frame, count frames from the click to the flash and enter the number.
Frequently asked questions
What is a good input lag?
Under 30 ms end to end is excellent for gaming; 30–50 ms is good. Above 80 ms most people notice sluggish controls.
Why can't a browser measure the monitor's delay?
The browser knows when a frame is sent to the display, not when pixels actually change. Only a camera or a light sensor can see that.
How do I lower input lag?
Enable your TV's Game mode, use a higher refresh rate, turn off V-Sync or use adaptive sync, and use a wired mouse.