Your Phone's GPS Might Be More Accurate Than It Claims

A GPS device you might use in a robot, drone, or even a smartphone is telling users one thing about its accuracy — about 16 feet (5 meters) — but behaving like it’s much more precise. A developer found that while the device claims its position could jump up to 16 feet due to noise, the actual movement between one second and the next is often just a few inches — sometimes even less than a foot. That’s a huge difference.

Why does this happen? The device is smoothing its signals internally. It takes multiple readings and averages them to give a steadier, more reliable-looking position on your screen. That’s helpful for navigation apps, but it can trick systems that rely on raw, fast updates — like a drone trying to land or a delivery robot avoiding obstacles. These systems expect fast, independent updates. When the GPS fakes stability by smoothing, it can make the robot think it’s exactly where it should be — when it’s actually off by several feet.

The developer shared a simple script to check your own GPS data. It compares the device’s stated accuracy with the actual movement between readings. Most users will find their GPS is smoother — and less truthful — than advertised. Some high-end GPS systems (like RTK fixed systems) don’t smooth as much, giving raw, real-time data, but they’re expensive and rare.

This matters because if you’re building a self-driving car, drone delivery service, or even using an autonomous vacuum, you need to know: Is your GPS telling the truth, or is it hiding how much it’s really moving? Trusting the smoothed version could lead to accidents or missed deliveries. The fix? Adjust how your navigation software interprets the GPS data — or invest in better hardware.

This issue affects robotics, drones, and even future self-driving cars that rely on GPS for positioning.