Make fair comparisons

How device latency affects your reaction time

Your online reaction time score combines your response with the delay of the screen, browser and input device. A faster display can change the recorded time even when your response has not changed. This guide explains the numbers you can calculate, the delays you cannot infer from them, and a practical way to compare sessions.

By ReactionTest.net · Updated October 3, 2026

60 Hz vs 144 Hz vs 240 Hz reaction time tests

Refresh rate describes how often a display updates. A nominal frame interval is 1,000 ÷ refresh rate milliseconds. At 60 Hz the interval is about 16.67 ms; at 144 Hz it is 6.94 ms. The difference between those intervals is 9.72 ms. That is a timing opportunity, not a guaranteed improvement in your score.

The cue can become visible at different points in the refresh cycle. Display processing, pixel response, scanout and browser rendering also matter. A frame interval is neither the delay of the whole display nor a value to subtract from every attempt.

On devices with variable refresh rates or power-saving modes, the active refresh rate may differ from the advertised maximum. Check the display settings used for that session before labeling it “144 Hz” or “240 Hz.”

Mouse polling rate, keyboard and touch input

A nominal polling interval is also 1,000 divided by the polling rate. For example, 125 Hz corresponds to 8 ms between reports and 1,000 Hz to 1 ms. These intervals do not describe the whole input path: switch behavior, firmware, connection, operating-system handling and event processing can add delay.

Mouse clicks, keyboard presses and screen taps also use different movements. Keep your finger position and input method consistent. Do not combine a touch session with a mouse session and interpret the difference as a change in your reflexes.

Wireless devices vary in design and connection. A Bluetooth device and a low-latency gaming receiver are different setups; “wireless” alone is not enough to predict the result. Measure repeat sessions under the same conditions instead of assigning one fixed delay to all wireless devices.

Why audio and visual scores are hard to compare

In the audio reaction time test, a tone must pass through the browser, audio system and speakers or headphones before you hear it. Bluetooth audio may add another part of that path. The page cannot know the exact instant the sound reaches your ears.

Visual and auditory tasks can differ in controlled experiments, but subtracting your browser audio result from your visual result does not isolate that biological difference. Keep sound-device details with the session and compare each mode with its own earlier results.

Does a high-resolution timer make a browser test accurate?

performance.now() provides a monotonic elapsed-time clock, as described in the W3C High Resolution Time specification. It helps avoid errors from changes to the wall clock. It does not measure when a pixel physically lights up, when a sound reaches you, or when your input switch first moves.

In a controlled experiment, Woods et al. (2015) measured display and mouse delays totaling 17.8 ms for their particular equipment. That correction applies to their setup. It is not a universal correction for your phone, monitor or mouse.

ReactionTest.net shows the raw browser result. We have not measured an accuracy margin for every device. The testing methodology explains exactly what the site records and calculates.

A practical protocol for comparing two setups

1. Choose one test mode and input method. Make a note of your browser, device, display setting and input device.
2. Keep the browser in the foreground and avoid changing tabs during an attempt. Finish a short practice set before recording a comparison set.
3. Record five valid attempts on setup A and five on setup B. Use the same hand and comfortable finger position.
4. Repeat in reverse order, B then A, to reduce the chance that practice or fatigue favors the second setup.
5. Compare the averages, medians and spread of the complete sets. Keep false starts separate and save the CSVs from the reaction time test.

This is a personal comparison, not laboratory calibration. You still cannot tell how much of a small difference comes from your attention, movement or the hardware. If the order changes the outcome or the sets overlap substantially, collect more sessions before drawing a conclusion.

Questions about device delay

Will a 144 Hz monitor make my reaction time 10 ms faster?

Not necessarily. The nominal frame intervals differ by about 9.72 ms, but cue timing within a cycle and other delays also affect the result. Compare actual repeated sessions instead of expecting a fixed gain.

Should I subtract my monitor's refresh interval?

No. A refresh interval is not a measured end-to-end delay. Subtracting it would create a corrected-looking number without measuring the correction.

Can a ruler test measure my device lag?

The ruler drop test avoids screen latency, but uses a different cue and hand movement. Its difference from a browser score is not a direct estimate of device lag.