Input response diagnostics

Controller Latency Test

Press buttons repeatedly and this controller latency test will show local event timing clues, browser freshness, and optional WebHID capability.

Latency Event Timeline

Button events and browser timestamp freshness are shown as practical latency clues.

No Controller Detected

Connect via USB or Bluetooth, then press any controller button to activate detection.

Browser freshness

Waiting

Excellent

Last button

Waiting

Press a controller button for an event marker.

Optional WebHID can be requested for compatible devices after a click.

Event markers

local only
Waiting for button events.

A Practical Latency Test For Browsers

A controller latency test in a web page cannot measure the exact moment your finger moved. It can show when the browser receives updated controller state, how fresh the current timestamp appears, and whether optional APIs such as WebHID are available for compatible devices. This gamepad latency test is therefore a practical timing surface, not a laboratory input rig.

The event timeline records button changes and displays browser freshness as a live metric. If the controller latency test shows long gaps, inconsistent updates, or stale timestamps, compare the polling rate test and try another connection mode. If the page looks stable but a game feels delayed, the delay may be in the game loop, display, streaming layer, or operating-system controller stack.

Optional WebHID is requested only after a button click. HID permissions can provide lower-level reports on some devices, but support varies and users should understand the prompt. The input latency test remains useful through the standard Gamepad API even when HID is unavailable or denied.

How To Compare USB, Bluetooth, And Apps

Run the controller latency test with one connection type at a time. Start with USB as a baseline, press the same button repeatedly, and watch the event list. Then reconnect over Bluetooth and repeat the same cadence. The absolute browser numbers may be approximate, but differences between modes can reveal unstable wireless behavior.

Avoid interpreting a single spike as proof. Browsers share CPU time with other tabs, extensions, capture tools, and the operating system. A good gamepad latency test uses repeated presses, a stable environment, and comparison against the polling rate timeline. If the problem appears only while streaming or recording, the browser input path may not be the cause.

Latency perception also depends on display refresh, game frame pacing, VSync, cloud gaming round trips, and television processing modes. This controller latency test focuses on the controller side of the chain so you can narrow the search rather than blaming every device at once.

Interpreting Freshness And Event Logs

Freshness is the time between the current browser clock and the latest gamepad timestamp. A small value suggests that JavaScript is seeing recent input state. A large value while you are actively pressing buttons suggests the browser is not receiving updates regularly, the tab is throttled, or the controller has not been activated.

The event log helps identify missed presses and repeated triggers. If every physical press appears once and clears quickly, the controller side is likely healthy. If one button repeats without touch, use the button mapping test to inspect its raw value. If updates arrive slowly, use the polling rate test for a longer interval chart.

When WebHID is available, it should be treated as an advanced comparison path. The input latency test does not force that permission because many users only need ordinary Gamepad API evidence. Clear unsupported states are better than aggressive prompts.

Diagnostic Glossary

Freshness

How recent the browser's latest controller timestamp appears to be.

Input latency

The delay between physical action and observed response, measured across a larger chain than this page can fully see.

HID report

A lower-level device message that may be available through explicit WebHID permission.

Questions Users Ask

Short answers for common diagnostic decisions on this page.

Can this page measure exact controller latency?

No browser page can know the physical switch time without hardware. It shows useful browser-side timing clues.

Why request WebHID?

Some compatible devices expose additional reports through HID. The permission is optional and only requested after a click.

Should I test latency or polling first?

Use polling first for update frequency, then latency when the controller still feels delayed.

Useful Next Checks

Check polling rate

Sample browser input intervals while moving or pressing controls.

Inspect button mapping

Confirm indexes, labels, analog values, and unusual layouts.

Read troubleshooting paths

Fix detection, Bluetooth, permission, browser, and mobile issues.

Open all tools

Choose the right diagnostic page for the controller symptom you see.