Joystick & Analog Stick Tester Online
Track real-time 2D coordinates (X, Y), polar angle and magnitude (r, θ), and 72-sector outer boundary circularity traces for Left and Right thumbsticks.
Plug in your controller & press any button, or test using keyboard emulation / auto demo.
Dual Analog Stick 2D Radar & 72-Sector Circularity Analyzer
Inspect live 2D Cartesian coordinates (X, Y), polar vector angle (r, θ), and outer boundary circularity across 72 angular sectors (5° each).
Release both thumbsticks completely. Verify whether the coordinate dot stays inside the dashed inner deadzone ring.
Push each stick firmly against the plastic rim and roll it slowly 2–3 full rotations to fill all 72 five-degree sectors.
Press straight down on Left Stick (B10) and Right Stick (B11) to confirm tactile click actuation.
r = 1.000 unit circle • Dashed green = 6% inner deadzoner = 1.000 unit circle • Dashed green = 6% inner deadzone|r - 1.000| between your recorded 72-sector outer trace and a mathematical unit circle (r = 1.000). Lower radial deviation indicates that the controller's firmware normalizes outer travel close to a circle, whereas higher radial deviation occurs when the firmware scales horizontal and vertical axes independently toward (±1.0, ±1.0) in the diagonals (producing a rounded-square trace where r > 1.000). Neither profile inherently indicates a hardware defect—check the radar polygon for smooth, symmetrical coverage and full reach across all four cardinal directions.Test all buttons, sticks, triggers, deadzones, and developer telemetry together.
Overview & Diagnostic Methodology
Use the dual radar scopes to inspect three aspects of thumbstick behavior: hands-off resting center stability, smooth 360-degree angular progression, and outer boundary geometry. As you roll each stick around the controller housing rim (>40% deflection), the analyzer records the maximum radius reached in every 5-degree sector and computes angular coverage, average radial deviation, and maximum corner deviation from a unit circle (r = 1.000).
How 72-Sector Circularity Works & Why Outer Traces Vary by Firmware
How the 72-Sector Outer Trace Is Calculated: As you push a thumbstick past 40% deflection (r > 0.400) and rotate it around the outer rim, this tool divides the 360-degree circle into 72 angular sectors of 5 degrees each. In every sector, it stores the farthest radial distance r = sqrt(X² + Y²) reached during your sweep. Once you have swept the perimeter, it compares those 72 outer points against a mathematical unit circle of radius 1.000 to compute Average Radial Deviation (Mean |r - 1.000|) and Maximum Radial Deviation.
Why Many Controllers Trace a Rounded Square (r > 1.000 in Diagonals): A common misconception is assuming that 0.0% circularity deviation means a "better" controller and a higher percentage means a "faulty" stick. In practice, many controller firmwares scale the horizontal (X) and vertical (Y) axes independently so both axes can approach ±1.000 when pushed into a 45-degree diagonal corner. Because Euclidean radius is r = sqrt(X² + Y²), independent axis saturation naturally produces a rounded-square outer trace where diagonal radius exceeds 1.000—ensuring games that check X and Y thresholds separately register full diagonal movement speed.
Circular Boundary Normalization vs. Independent Axis Scaling: Other controllers normalize or clamp their outer boundary in firmware so that r = sqrt(X² + Y²) stays close to 1.000 at all angles, producing a near-circular polygon with lower radial deviation. Neither normalization strategy is universally superior—what matters diagnostically is that your outer trace is smooth and symmetrical across all four quadrants without flat clipped edges, sudden inward dips, or cardinal directions that fail to reach full travel.
Measurement & Telemetry Classification
Technical distinction between direct hardware reads, client-side algorithms, and educational thresholds.
- Raw W3C Gamepad API horizontal and vertical axis floats (Axes 0 & 1 for Left Stick, Axes 2 & 3 for Right Stick).
- Digital thumbstick press switch states for B10 (L3 / LS) and B11 (R3 / RS).
- Instantaneous polar vector magnitude r = sqrt(X² + Y²) and directional angle θ in degrees (0° to 360°).
- Maximum outer radius recorded per 5-degree angular bin across 72 sectors (ignoring inner movements <= 0.400).
- Angular coverage percentage, mean radial deviation (Avg |r - 1.000|), and peak corner deviation (Max |r - 1.000|).
- Rounded-square vs. circular firmware normalization: why many controllers intentionally exceed r = 1.000 in the diagonals.
- Physical anti-friction rings and shell bezels: how plastic housing wear or aftermarket shells alter outer perimeter traces.
- Potentiometer wiper tracking vs. Hall Effect / TMR magnetic sensors: how sensor mechanics affect angular smoothness.
Key Diagnostic Parameters
How to Test Step-by-Step
- 1Connect your controller via USB or Bluetooth and press any physical button to wake the browser Gamepad API feed.
- 2Step 1 (Hands-Off Center Check): Leave both thumbsticks untouched and confirm whether the live coordinate dot rests inside the dashed inner deadzone ring.
- 3Step 2 (360° Outer Circularity Sweep): Push the Left Stick firmly against the outer plastic rim and rotate it slowly 2 to 3 full turns until Angular Coverage reaches 95%–100%, then repeat on the Right Stick.
- 4Step 3 (L3 / R3 Click Check): Press straight down on the Left Stick (B10) and Right Stick (B11) to verify that the Click Verified badge lights up.
- 5Use "Reset Trace" on either stick (or "Reset Both Traces" at the top) to clear recorded sectors and repeat the sweep at a slower, steadier rotation speed.
What This Test Verifies
Left Stick (Axes 0 & 1, Switch B10) and Right Stick (Axes 2 & 3, Switch B11) are sampled on each browser animation frame. Outer 72-sector radial deviation compares recorded maximum deflection per 5-degree sector against a mathematical unit circle (r = 1.000).
Defines Axes 0–3 directional orientation and B10/B11 stick click indices.
Details floating-point coordinate arrays exposed for joysticks and thumbsticks.
Frequently Asked Questions
Does a higher circularity deviation percentage mean my controller is defective?
No. Average radial deviation simply measures the geometric distance |r - 1.000| between your recorded outer trace and a mathematical unit circle. Controllers whose firmware scales X and Y independently toward (±1.0, ±1.0) in the diagonals intentionally produce a rounded-square trace with higher radial deviation so diagonal movement reaches full speed in games.
What should I actually look for on the 72-sector circularity radar?
Look for symmetry and smooth coverage rather than chasing a 0.0% radial deviation figure. A healthy thumbstick traces a smooth, even boundary across all 72 sectors and reaches at least 0.950 to 1.000 on the Up, Down, Left, and Right crosshairs. Flat inward dents, missing angular sectors, or a cardinal direction that stops short at 0.800 indicate physical shell obstruction, sensor wear, or uncalibrated axis bounds.
Why does Angular Coverage stay below 100% when I rotate the stick quickly?
Web browsers poll gamepad states once per animation frame (for example, 60 times per second on a 60Hz monitor). If you spin the thumbstick too quickly, the stick can jump across a 5-degree sector between frames. Rotate the stick slowly and steadily around the rim for 2 to 3 turns to fill all 72 sectors.
What determines whether a controller produces a circular or rounded-square trace?
The outer trace shape is determined by how the controller firmware normalizes raw sensor bounds and by the physical plastic bezel ring. Some firmwares clamp the outer radius directly to r = 1.000 (a circular gate), while others allow independent horizontal and vertical saturation in the corners (a rounded-square gate). Some customizable controllers even let you switch between circular and expanded-diagonal modes in their companion software.
How do I reset the purple outer circularity trace?
Click the "Reset Trace" button on the top-right corner of either stick card to clear that stick’s 72 sectors, or click "Reset Both Traces" at the top of the tool to clear both sticks at once.