Calibrating Raw Mouse Input and Fixing Pointer Lock Coordinate Drift in 3D Web Shooters

When playing first-person shooters in the browser (such as Krunker, Ev.io, or Shell Shockers), accurate aim is everything. Yet many players notice a subtle but infuriating sensation: when you flick your mouse quickly, your crosshair travels farther than when you move it slowly across the exact same mousepad distance. Worse, fast camera rotations can occasionally stutter or hit invisible boundaries.

This occurs because standard browser pointer events are subject to operating system mouse acceleration curves and coordinate clipping unless developers and players configure the HTML5 Pointer Lock API for raw unadjusted movement.

This guide explains how pointer lock works and how to achieve true 1:1 raw mouse tracking in modern browsers.

1. Pointer Lock vs Raw Unadjusted Movement

When a 3D web game locks your cursor (element.requestPointerLock()), the browser hides the physical cursor and begins delivering relative motion delta values: movementX and movementY.

By default:

• On Windows and macOS, the operating system applies mouse acceleration (e.g., Windows “Enhance pointer precision”).
• If you move the mouse fast, Windows artificially multiplies the delta, ruining your muscle memory.

To solve this, the W3C Pointer Lock specification added the unadjustedMovement parameter:

canvas.requestPointerLock({
  unadjustedMovement: true
});

When unadjustedMovement is true, the browser bypasses Windows acceleration and delivers raw, unprocessed counts directly from the mouse sensor!

2. Step 1: Disable Windows Enhance Pointer Precision

1. Press Windows Key + R, type main.cpl, and press Enter to open Mouse Properties.
2. Switch to the Pointer Options tab.
3. Uncheck “Enhance pointer precision”.
4. Set the pointer speed slider to the 6th notch (exact 1:1 multiplier).
5. Click Apply.

3. Step 2: Enabling Raw Input in Google Chrome

Chromium includes an internal flag that forces high-precision raw pointer capture:

1. Open Chrome and enter: chrome://flags/#enable-pointer-lock-options
2. Toggle the flag to Enabled.
3. Relaunch Chrome. Browser shooters that request unadjusted movement will now receive raw DPI sensor data with zero cursor acceleration.

Related Guides & Documentation

• Category Hub: Browse all guides in Controls, Latency & Audio Fixes
• Related Guide: Why 1000Hz and 8000Hz Mouse Polling Rates Choke Chrome Main Thread and How to Fix It — How ultra-high polling rate gaming mice flood the Chromium event loop with micro-events, causing frame drops, and how to stabilize polling rates.
• Related Guide: Comparing Exclusive Fullscreen vs Borderless Windowed Input Latency in Chromium and Firefox — How the HTML5 Fullscreen API interacts with the Windows Desktop Window Manager (DWM) compositor and how to minimize input lag in full-screen games.
• Related Guide: Calibrating Analog Stick Deadzones and Trigger Axes for PlayStation Controllers in Web Games — How the HTML5 Gamepad API maps DualShock 4 and DualSense axes, and how to calibrate stick drift and deadzones using browser consoles.