You can do offline positioning using Bluetooth beacons. With the Web Bluetooth API, a web app can scan nearby beacons, read their signal strength (RSSI), and estimate your position on a pre-made map, while combining barometer and motion sensors to track floor level and movement for (x, y, z) coordinates. Accuracy depends on beacon placement, calibration, and environmental factors like walls or interference, and RSSI-based positioning is inherently noisy, typically only accurate to a few meters. Web Bluetooth also has browser and platform limitations, and sensor-based tracking can drift over time without recalibration, so while this approach works in principle, it is not highly precise.