Controller Diagnostic

Circularity Test

Test thumbstick circularity error and outer range of motion on PS5, Xbox, and Switch gamepads. Plot 360-degree outer boundaries in real time.

Rotate both thumbsticks 360 degrees to measure circularity...

No Controller Detected

Left Stick Circularity

0.0% Error

Points Samples 0

Avg Radius 0.000

Outer Error Perfect

Right Stick Circularity

0.0% Error

Points Samples 0

Avg Radius 0.000

Outer Error Perfect

Circularity Error Ratings

0.0% – 5.0% (Excellent)

Near-perfect circular boundary. Consistent diagonal aiming sensitivity in shooters.

5.1% – 12.0% (Standard Factory)

Normal factory stick variance. Typical for standard PS5 and Xbox controllers.

> 12.0% (High Error)

Noticeable diagonal distortion. Octagonal physical gate or worn potentiometer housing.

How to Get Started

Just three steps to run a complete controller test and understand your controller's health status.

Connect Controller

Connect your controller to your computer via USB cable or Bluetooth. If the browser doesn't respond, press any button on the controller to activate the connection.

Button Detection

Press each button in the visual interface and confirm the corresponding area lights up on screen. This helps troubleshoot unresponsive or double-clicking buttons.

Sticks & Vibration

Rotate the sticks to check linearity and drift issues; click the vibration test button to feel if the left and right motor feedback is working properly.

What would you like to do next?

Select a diagnostic calibration suite, deadzone analyzer, or high-frequency overclock tool.

Fix

Repair & Calibration

Calibrate zero-point offsets or follow step-by-step repair guides.

WebHID Calibration

Optimize

Game Deadzones

Calculate exact radial vs axial deadzone overlays for Fortnite, Apex, & COD.

Deadzone Calculator

Telemetry

Overclock & Circularity

Verify true hardware polling Hz stability and statistical circularity grades.

Hz & Circularity Tools

Play & Practice

Practice what you just tested

Turn your test results into skill. These arcade games train the exact inputs you just measured — drift, buttons, triggers, D-pad and reaction time.

Browse all games

+50 XP

Stick Sniper

Aim with the right stick, fire with R2/RT, and track targets before they vanish.

Play

+100 XP

Nova Blaster

Twin-stick arena shooter — move, aim, and survive waves.

Play

Why Analog Stick Circularity Is Critical for Competitive Gaming

When playing first-person shooters or racing simulators, game engines translate 2D analog stick coordinates (X, Y) into camera rotation or steering angle. If your thumbstick housing produces a squared or distorted outer boundary, diagonal inputs reach 100% magnitude earlier than cardinal inputs.

Hall-Effect vs Potentiometer Circularity

Modern Hall-effect thumbstick replacements feature digital anti-aliasing algorithms that calibrate circularity down to sub-1.0% error rates, delivering perfectly uniform 360-degree turning speeds.

Frequently Asked Questions

Everything you need to know about testing your controller.

What is controller circularity error?

Circularity error measures how far a thumbstick's actual maximum movement boundary deviates from a perfect 360-degree mathematical circle. Lower error percentages indicate better diagonal movement accuracy.

What is a good circularity error score?

An error score below 5.0% is considered excellent. Factory DualSense and Xbox controllers typically score between 5% and 12% due to squarish outer gate restrictors.

Does circularity affect aiming in FPS games?

Yes! High circularity error distorts diagonal aiming sensitivity, causing diagonal crosshair movement to feel faster or slower than cardinal (horizontal/vertical) aiming.

How this test works & its limits

This test reads your controller through the browser's standard Gamepad API — no drivers, no installs, nothing leaves your device.
Readings depend on connection mode: Bluetooth reports at lower rates than USB. Compare like-for-like (wired vs wired).
We measure the input reaching the browser — display lag and game-engine queues are outside this test's view.
A clean reading now does not guarantee no drift in-game: deadzones differ per game, and wear develops over time. Use the Drift Timeline to track yours.
This is a diagnostic, not a hardware-lab certification. For repair or RMA decisions, confirm with a second run or second tool.

Read the full methodology

100% Client-Side

All Gamepad API data stays in your browser. Zero tracking or data collection.

Instant Results

No downloads, plugins, or software installation needed. Works instantly.

Free Forever

No paywalls, subscription requirements, or hidden usage limits.