Stick Circularity & Snapback Test
When you push a stick around its edge, it should trace a perfect circle. In reality most sticks trace a slightly squarish or uneven shape. The difference is called circularity error. High error means diagonal movement is slower or faster than straight movement, which affects aim and movement in games.
Snapback is what happens when you flick a stick and let go: it springs past the centre and briefly registers movement in the opposite direction. This page tests both.
Stick Circularity & Snapback Test
Trace stick orbit coordinates to measure circularity error percentage and snapback oscillation.
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How to use it
- Connect your controller and press any button.
- Circularity: press Start, then slowly rotate each stick around its outer edge three times, pressing gently against the rim.
- Check the shape drawn on screen and the circularity error percentage.
- Snapback: switch to snapback mode, push the stick fully in one direction and let go. Repeat in each direction.
- Read how far past the centre the stick went.
What your results mean
Circularity error:
Error What it means
Under 5% Excellent. Very even response in every direction.
5â15% Typical for most controllers
Over 15% Uneven. Diagonals behave noticeably differently, often from wear.
Snapback
Overshoot What it means
Under 10% Normal
10â25% Noticeable. Can cause small unwanted movements after quick flicks.
Over 25% Strong snapback. A small deadzone or a controller with snapback correction helps.
Both results can change with wear, so test again if a controller starts to feel different.
Why circularity error happens
A stick moves inside a round or slightly square opening, and the sensors measure up/down and left/right separately. When the two measurements don't line up perfectly at the diagonals, the shape traced isn't a perfect circle.
Manufacturers and drivers sometimes reshape the output on purpose, so a slightly square shape isn't automatically a fault. What matters is whether it changes over time: a stick that used to test well and now shows a much higher error is wearing.
What circularity error looks like in games
With high circularity error, pushing the stick diagonally gives a different result from pushing straight. In a shooter, aiming diagonally might be faster or slower than aiming left and right. In a racing game, steering at the edges can feel uneven. When walking, diagonal movement might not reach full speed.
Most players don't notice small amounts. It becomes noticeable in competitive games, where consistent aim in every direction matters, and when the error is much larger on one stick than the other.
Shape drawn What it means
Close to a circle Even response in every direction
Rounded square Diagonals reach further than straight directions
Flattened on one side Worn or obstructed in that direction
Jagged edge Dirty or failing sensor
Why some controllers draw a square on purpose
Some controllers, drivers and adapters reshape the stick output so diagonals reach the corners of a square. That makes diagonal movement reach full speed in older games. It shows up here as a high circularity error even on a perfectly healthy stick.
If your new controller shows a rounded square, that's probably the design. What matters is whether the shape changes over time or differs between the two sticks.
How snapback affects your aim
Snapback happens when you flick a stick and let go. The stick springs back past the centre before settling, and for a split second the game sees a small push in the opposite direction. In a shooter, your aim can twitch the wrong way after a quick flick. In a platformer, your character might briefly turn around.
A healthy stick has a small amount of snapback that games usually ignore. Worn springs and loose stick modules increase it.
Reducing snapback and circularity issues
A small deadzone hides most snapback, because the overshoot is usually brief and close to the centre. Our Deadzone Calculator includes snapback in its measurement for this reason.
For circularity, many games and Steam Input let you choose a circular or square stick response. If your controller's shape doesn't suit a game, switching that setting can help. If the shape has changed over time, the stick is wearing and recalibration or replacement is the longer-term fix.
Comparing two controllers or two sticks
Run the test on both sticks and compare their numbers. A big difference between left and right usually means one stick is more worn. Testing two controllers of the same model also shows quickly which one is in better condition.
Your results are saved in this browser, so you can test again after cleaning or calibrating and see whether it helped.
How to take an accurate test
Rotate the stick slowly and evenly around its full edge, pressing it firmly against the outer limit. Do several full circles in each direction. Rotating too quickly or not reaching the edge can make the result less accurate.
Test both clockwise and anticlockwise. Some worn sticks show different results in each direction.
Circularity and stick drift
Circularity and drift are related but different. Drift is about the centre, while circularity is about the edges. A stick can have perfect circularity and still drift, or no drift and poor circularity.
Use our Deadzone Calculator to check drift and this test to check the edges.
Hall effect and TMR sticks
Hall effect and TMR sticks often show very consistent circularity, because their sensors don't wear the same way. Their shape may still not be a perfect circle, depending on how the controller processes the output.
Testing them over time shows whether they stay consistent.
Outer deadzone settings
Some games have an outer deadzone setting that controls when the stick counts as fully pushed. If your circularity test shows the stick doesn't quite reach the edge in some directions, increasing the outer deadzone slightly can help.
Keep it small to avoid losing precision near the edge.
Calibration and circularity
Calibrating a stick sets where its edges are, which can improve circularity. On PlayStation controllers, our PS Stick Calibration tool can help. On Switch, the console has stick calibration in its settings. On PC, Steam Input offers calibration too.
Test again after calibrating to see whether it helped.
What the numbers mean
The average circularity error shows how far, on average, the stick's edge is from a perfect circle. Lower is better. The shape drawn shows where the stick falls short or goes past the circle.
Look at both. A low average with one flat spot can still cause problems in one direction.
Why the left and right sticks differ
The left stick usually gets more use, because it controls movement in most games. That means it often wears faster and shows a higher circularity error than the right stick.
If one stick is noticeably worse than the other, that stick is wearing. Keep an eye on it and retest over time.
Testing a used controller
When buying a second-hand controller, the circularity test is a quick way to check stick wear. A smooth shape similar on both sticks is a good sign. Flat spots, jagged edges or a big difference between sticks suggest heavy use.
Combine it with our Controller Health Check for a full picture.
Third-party controllers and circularity
Third-party controllers vary a lot in how they shape stick output. Some produce near-perfect circles, others very square shapes. Neither is necessarily better; it depends on what you're used to and how your games handle it.
Compare the result with reviews of the same controller to see whether yours is typical.
Snapback in fighting and platform games
Snapback can cause unwanted inputs in games where precise direction matters. In platformers, letting go of the stick can briefly push your character the other way. In fighting games, it can cause an accidental back input.
If you notice this, a slightly larger deadzone or a controller with stronger springs can help.
Cleaning around the stick
Dust and grime around the base of the stick can stop it reaching the edge in some directions, which shows up as a flat spot. Blow compressed air around the base while moving the stick in circles, then test again.
If the shape improves, the problem was dirt. If not, the stick itself is likely worn.
Common problems
Some controllers and drivers limit the stick's corners. It's common on PC controllers and not always a fault.
Rotate slowly and press evenly against the edge. Take the best of three tries.
Frequently asked questions
Does circularity error matter in games?
Mostly for aiming and precise movement. In casual play most people won't notice under 15%.
Can I fix high circularity error?
Some games and Steam Input let you adjust stick response. If it's from wear, recalibrating or replacing the stick helps.
What is snapback?
The stick springing past centre after you let go, briefly sending an input in the opposite direction.
Is a 10% circularity error bad?
No. Many healthy controllers measure in that range.
Can cleaning improve circularity?
Sometimes. Debris around the stick can block movement in one direction.
Does snapback get worse with age?
Often. Worn springs and loose parts increase overshoot.
Should I test both sticks?
Yes. They wear at different rates.
Does this work on Switch Joy-Con?
Yes, if your browser detects them.
Does circularity affect aim?
Yes, especially when aiming diagonally.