Causes
- IMU sensor drift accumulation in the X1 spatial chip — the XREAL One Pro's custom X1 chip relies on a built-in inertial measurement unit (IMU) combining a 3-axis gyroscope, 3-axis accelerometer, and a magnetometer to calculate head position and anchor the virtual screen in 3D space. Over time, the gyroscope's bias drifts due to temperature changes (the X1 chip warms up during operation, shifting the gyro's zero-rate output). Without a visual reference (the XREAL One Pro lacks outward-facing cameras for SLAM-based drift correction), the accumulated IMU error causes the anchored screen to slowly shift rightward — typically 1–3 degrees over 15–30 minutes
- Magnetic interference from nearby electronics — the X1 chip's magnetometer is used for initial heading reference and yaw drift compensation. Ferromagnetic materials (speakers, laptop hinges, metal desks, or magnetic phone mounts) within 10–15 cm of the glasses can distort the local magnetic field. When the magnetometer reading is biased by external interference, the fusion algorithm incorrectly interprets a stable head position as a slow rotation, commanding the anchored screen to drift in the opposite direction
- Poor initial calibration on a non-level surface — the XREAL One Pro performs automatic gyroscope bias and gravity vector calibration when first powered on while stationary. If the glasses are moved or rotated during the initial 3-second calibration window (e.g., you put them on and turn your head immediately after connecting), the bias offsets are computed incorrectly. This mis-calibration causes the anchored screen to drift from the very start, often immediately after the anchor is set
- Firmware bug in the sensor fusion algorithm — multiple community reports on the XREAL subreddit and XREAL's official developer forum have documented a persistent drift issue in anchor (3DoF) mode on the XREAL One Pro. The X1 chip's proprietary sensor fusion algorithm that combines gyroscope, accelerometer, and magnetometer data can diverge when the glasses experience sustained low-frequency vibration (e.g., walking, sitting in a moving car, or using the glasses on public transit). This is a known software-side issue that XREAL has addressed in incremental firmware updates but has not fully eliminated for all use cases
- Temperature-induced calibration drift — the X1 spatial chip's gyroscope bias is temperature-dependent. When you first put on the XREAL One Pro, the chip is at ambient temperature (~22°C). After 10–15 minutes of operation, the chip warms to ~38–42°C, shifting the gyroscope's zero-rate output by several degrees per minute. The sensor fusion algorithm attempts to compensate with a temperature-modelled bias tracking, but the compensation model has limited accuracy during rapid temperature transitions (e.g., moving from an air-conditioned room to outdoors)
How to Fix
- Perform a stationary gyroscope recalibration: place the XREAL One Pro on a flat, level, non-metallic surface (a wooden table or plastic desk — avoid metal laptop stands or steel desks). Leave the glasses untouched and stationary for a full 30 seconds. This allows the X1 chip's automatic gyroscope bias calibration to run to completion. After 30 seconds, pick up the glasses, put them on, and switch to Anchor mode. The screen should stay locked in position for significantly longer before drift becomes noticeable
- Re-calibrate the 3DoF tracking by switching modes: while wearing the glasses, switch from Anchor mode to Follow mode (press the mode button on the right temple). Leave Follow mode active for 10 seconds, looking straight ahead without moving your head. Then switch back to Anchor mode. This forces the X1 chip to re-sample the IMU bias offsets and re-initialise the sensor fusion state machine without needing to reboot the glasses. Many users report that this simple mode-toggle reset clears drift for another 20–30 minutes of use
- Power cycle the glasses and let them warm up before using Anchor mode: disconnect the XREAL One Pro from your source device, wait 30 seconds, then reconnect. Immediately after connecting, leave the glasses on a flat surface (not on your head) for 2 minutes before putting them on. This allows the X1 chip to complete its full temperature ramp and automatic multi-stage bias calibration. Once the glasses have thermally stabilised, put them on, enable Anchor mode, and the drift rate will be significantly lower because the gyroscope bias was calibrated at operating temperature rather than at room temperature
- Move away from magnetic interference sources: if you use the XREAL One Pro near a laptop, desktop speakers, wireless charging pad, or a metal desk, move at least 30 cm away from these objects before setting the anchor. The magnetometer is most sensitive to ferromagnetic distortion. If drift returns when you move closer to a specific device, that device is the interference source. For laptop use, try positioning the glasses away from the laptop's hinge area (which contains steel components and magnets) by setting the anchor in Follow mode and then switching to Anchor with your head turned away from the laptop
- Update to the latest firmware: connect the XREAL One Pro to your computer and run the XREAL Firmware Updater from xreal.com/us/support/one-pro. XREAL has released multiple firmware updates (versions 1.6.0 and later) that include improved sensor fusion algorithms with better temperature compensation modelling and reduced drift in Anchor mode. The firmware update also updates the X1 chip's gyroscope bias tracking filter coefficients, which directly addresses the warm-up drift issue. Check the firmware changelog for "improved 3DoF tracking stability" or "Anchor mode drift reduction"
- Use Follow mode as a fallback when drift is unacceptable: press the mode button on the right temple to switch from Anchor mode to Follow mode. In Follow mode, the virtual screen moves with your head but stays centred in your field of view — drift is not applicable because the screen position is relative to the glasses, not to the world. While Follow mode lacks spatial anchoring, it eliminates drift entirely. This is the most reliable workaround until you can complete the calibration and firmware steps. For tasks that genuinely need anchoring (watching a movie while turning your head away), re-calibrate with step 1 before each session
- Perform a full factory reset of the X1 chip: with the glasses connected to a power source (USB-C charger), press and hold both the brightness up and brightness down buttons (the top and bottom buttons on the right temple) simultaneously for 15 seconds. The electrochromic dimming will flash three times, indicating a full factory reset. This clears all calibration data stored in the X1 chip's non-volatile memory, including any corrupted gyroscope bias offsets from previous sessions. After the reset, perform step 1 (stationary recalibration) before using Anchor mode
- If drift persists after all software and calibration steps, the IMU hardware may have a defect — specifically, a gyroscope with excessive bias instability or a magnetometer with degraded sensitivity. Contact XREAL Support (support.xreal.com) for a warranty evaluation. The XREAL One Pro carries a one-year limited warranty, and several community members have reported that RMA replacements for the drift issue have units with better-performing IMUs. Note that a small amount of drift (less than 1 degree per 10 minutes) is considered normal for IMU-only 3DoF tracking without visual SLAM cameras — the above steps aim to reduce drift to this acceptable baseline