Car Speedometer
SpeedCheck needs your device's location to measure speed. Your browser will ask for permission when you tap Start Tracking — your location is never stored or sent anywhere.
Do not interact with this device while driving. Have a passenger operate it, or mount it securely and glance only when safe to do so.
A secondary speed reference, not a replacement
This tool gives you a GPS-based speed-over-ground reading, useful for comparing against your car's built-in speedometer out of curiosity or for cross-checking in a rental or unfamiliar vehicle. It is not a substitute for your car's instrument cluster, which remains the speed you should rely on while driving.
Have a passenger operate the phone, or mount it securely where you can glance at it briefly and safely — read the full GPS vs. vehicle speedometer guide for why the two numbers rarely match exactly.
Other speedometers
Related guides
Frequently asked questions
- Will this match my car's speedometer exactly?
- Usually not exactly. Factory speedometers and GPS measure speed differently and are affected by different things — tire size and pressure for the former, satellite signal quality for the latter. See the GPS vs. vehicle speedometer guide for details.
- Can I use this instead of my dashboard speedometer while driving?
- No. Treat it as a secondary reference, not a replacement for your vehicle's instruments. Mount your phone securely before driving and don't interact with it in motion — see the safety notice below.
- Does it work without cell signal?
- GPS positioning itself doesn't require cell signal once a fix is acquired, though the page needs to load once first and some phones use network assistance for a faster initial fix.