Circularity Test | Check Your Analog Stick Roundness Now
Rotate each stick at full deflection and watch the traced path build live against a reference circle, with an average error percentage and a quadrant by quadrant breakdown. Works with PS5, PS4, Xbox, Nintendo Switch, and generic USB or Bluetooth controllers.
Push each stick fully to its edge, then rotate slowly and steadily, covering the full circle at least twice. Points are only captured near full deflection.
Left stick
Right stick
Slow, deliberate rotation at full deflection produces the most reliable trace.
Connect
Plug in over USB or pair over Bluetooth, then press any button so the browser detects it.
Push to the edge
Push a stick fully to its mechanical limit before rotating, points are only captured near full deflection.
Rotate slowly
Trace the full circle at least twice, moving steadily rather than quickly.
Read the result
Compare the average error and quadrant breakdown against the reference table below.
Average error is the mean deviation of every captured point from a perfect unit circle at full deflection.
| Average error | Verdict | What it means |
|---|---|---|
| Under 5% | Excellent | Precise enough for competitive gaming and precision aiming. |
| 5 to 10% | Good | Typical of most healthy consumer controllers, no practical concern. |
| 10 to 15% | Functional | Noticeable if you look for it, worth monitoring over time. |
| Above 15% | Poor | May cause visible accuracy issues, uneven aiming or turning in games. |
Rotating a stick at full deflection should trace a smooth circle, since every angle is the same physical distance from center. When the underlying sensor reads angles unevenly, the traced shape stretches, flattens, or develops small bumps instead of staying round, and that inaccuracy translates directly into inconsistent aiming, uneven turning in racing games, and unpredictable movement wherever precise directional control matters.
Quadrant errors break that overall inaccuracy down by direction, right, up, left, and down. A stick with roughly even error across all four quadrants usually points to general sensor wear or a lower quality potentiometer overall. A stick with error concentrated heavily in one or two quadrants more often points to a specific mechanical issue on that side, such as uneven wear on one part of the contact strip.
Circularity and stick drift are related but different problems. Drift is unwanted movement reported while the stick sits at rest. Circularity is inaccurate movement reported while the stick is actively being moved. A stick can fail one test and pass the other, though both often appear together as a sensor wears down over time. Check the Stick Drift Test alongside this one for the full picture.
This test works with any controller your browser recognizes as a standard gamepad, including these commonly tested models.
Flat spots or bumps in the trace
Uneven readings across the circle often point to a worn or lower quality sensor.
Check sensor typeOne quadrant much worse than others
Error concentrated on one side usually points to localized mechanical wear.
Browse the Fix guidesAlso check for stick drift
Circularity and drift often appear together as a stick sensor wears over time.
Run the Stick Drift TestRun the full controller benchmark
Circularity is one part of a complete health check. Run every diagnostic in sequence and get one overall score for your controller.
Run the benchmarkWhat is a circularity test
A circularity test measures how closely the shape traced by an analog stick at full deflection matches a true circle. A healthy stick traces a smooth, round path, while a worn or misaligned stick produces bumps, flat spots, or an uneven oval.
How do I get an accurate circularity reading
Push the stick fully to its mechanical edge and rotate it slowly and steadily, covering the full 360 degrees at least twice. Moving too quickly skips points and produces a less reliable trace.
What counts as a good circularity error percentage
Under 5 percent average error is excellent, suitable for competitive gaming and precision aiming. 5 to 10 percent is good and typical of most consumer controllers. 10 to 15 percent is functional but noticeable. Above 15 percent may cause visible accuracy issues in gameplay.
Why does my stick have flat spots in the trace
Flat spots are often caused by mechanical limitations in a potentiometer style sensor, or physical wear on the internal components after extended use. Hall effect sticks typically produce a rounder, more consistent trace.
What are quadrant errors
Quadrant errors show how accuracy varies across the four main directions, right, up, left, and down. Uneven scores across quadrants often point to a mechanical issue or uneven wear concentrated on one side of the sensor rather than a uniform problem.
Can poor circularity be fixed
Minor circularity issues can sometimes be compensated for with an in game sensitivity curve or a wider deadzone. Severe circularity errors typically require replacing the analog stick module or the controller itself.
Is circularity the same thing as stick drift
No. Drift is unwanted movement reported while the stick is at rest. Circularity is inaccurate movement reported while the stick is actively being moved. A stick can have one problem without the other, though both often appear together as a sensor wears.
Does Hall effect fix circularity problems
Hall effect and TMR sensors generally produce rounder, more consistent traces since they read position magnetically rather than through a physical contact strip, but manufacturing tolerance still varies between individual sticks and controller models.
Can I test a PS5 DualSense controller's circularity here
Yes. The DualSense works over both USB and Bluetooth, and both analog sticks are traced live in this tool.
Can I test an Xbox controller's circularity here
Yes. Xbox Series X and S, Xbox One, and Xbox Elite controllers are all supported over USB and Bluetooth.
Does this work with a Nintendo Switch Joy Con
Yes, when the Joy Con is recognized as a standard gamepad by your browser.
Do I need to install anything to run this circularity checker
No. This tool runs entirely in your browser using the Gamepad API. There is nothing to download and no account to create.
Why does my trace only cover part of the circle
Points are only captured near full deflection, so if you do not push the stick all the way to its mechanical edge, or you only rotate through part of the full range, the trace will look incomplete rather than inaccurate.
Does this work on mobile phones
Yes, on any mobile browser that supports the Gamepad API and a controller paired over Bluetooth or connected through a USB adapter.
Is my stick position data stored anywhere
No. Every reading happens locally in your browser and is not sent to a server unless you choose to export a report yourself.