Input Lag Test

Record scoreless browser reaction timing across the full human, input, browser, system, graphics, and display path.

This check runs directly on this page without requiring fullscreen. Review what this browser test can and cannot measure.

Before you start

  • Use the same input device and display mode for every comparison.
  • Close heavy background work and wait until you are ready for five trials.

How to run this check

  1. Start the five-trial browser reaction task
  2. Wait for each randomized green cue, then respond with a pointer, touch, Space, or Enter
  3. Review the median and individual trials as a scoreless combined-path observation
  4. Keep the same browser, input device, display mode, and background workload for comparisons
  5. Use dedicated measurement hardware when isolated display latency is required

What this browser test can tell you

Can help you check

  • Human reaction time through the browser input path.

Cannot measure

  • This test cannot isolate monitor input lag or pixel response time.
Setup, interpretation, and sources

Recommended setup

  1. Use the same mouse, keyboard, or touch input for each run.
  2. Close distracting apps and complete several attempts.

How to interpret what you see

  • Record the median of several attempts and compare only runs made under the same conditions.
  • Human response, input-device latency, browser scheduling, operating-system load, graphics settings, and the display path are combined in browser reaction timing.
  • Isolated display latency requires a photodiode, a high-speed camera, or a dedicated latency tester.

Methodology reviewed:

Browser reaction task

  1. Keep the same browser, input device, display mode, and background workload.
  2. Choose Start, then wait for the panel to turn green.
  3. Respond with a pointer, touch, Space, or Enter. Early responses restart that trial.
  4. Complete five trials and compare runs only under matching conditions.

No trials recorded.

How to interpret a run

Treat the median and individual trials as a repeatable personal observation, not a display grade. Compare the spread between trials and repeat when you are rested and the system is idle.

Reversible checks include keeping the same input device, closing heavy background work, confirming the intended display mode, and repeating without changing several settings at once.

Isolating display latency requires an external reference plus a photodiode, high-speed camera, or dedicated latency instrument. Consult current product documentation for model-specific modes.