Online Speedometer Pro is a free, high-precision web-based GPS speedometer and odometer for cars, bicycles, and airplanes. Built with modern HTML5 Geolocation, it offers 7 customizable gauge themes (Digital & Nostalgic Mechanical Analog), a windshield HUD mirror mode for night driving, an automatic 0-100 km/h acceleration timer, and audio speed warnings—all without installing any mobile app.