- Tesla browser: tap the lock icon by the address bar → Site settings → allow Location, then reload.
- Chrome / Edge: tap the icon left of the address → Permissions → Location → Allow.
- Safari (iPhone): Settings → Privacy & Security → Location Services → Safari Websites → While Using.
Engine
More settings
How readily acceleration turns into throttle, and how late it shifts.
From a muffled stock engine to a lumpy cam on open pipes.
Pops and bangs on lift-off and shifts. 0% runs clean.
How to use it
- Parked: open this page in your car's browser and bookmark it.
- Pick an engine, tap Start engine, and allow location access.
- Turn up the media volume and drive. Accelerate harder for higher revs and later shifts.
- At a stop, hold Hold to rev to blip the throttle.
- Leave the page open. Browsers mute sound from pages in the background.
FAQ
Is it really free?
Yes. No trial, no daily limit, no account, no ads. OpenRev is open-source (MIT), so you can host your own copy too.
Why does it need my location?
It reads your speed so the engine revs and shifts with the car. Location is processed only in your browser and never sent anywhere. OpenRev has no server.
Does it play through the external Boombox speaker?
No. Browser audio plays through the cabin speakers, like music.
How is the sound made?
Each engine is synthesized live, firing pulse by firing pulse, from its cylinder count, bank layout and exhaust tuning. Nothing loops, so it responds to every change in speed and throttle.
Why is there a delay?
Speed comes from GPS. In a Tesla, revs trail the car by about half a second. Phones update GPS less often, so expect 1–2 seconds there. OpenRev extrapolates acceleration to hide some of this.
Does it work in other cars or on a phone?
Yes. It works in any modern browser with Web Audio and location. On a phone, connect to the car's speakers over Bluetooth.
The sound stopped, or won't start.
Keep the page in the foreground and tap the screen once if the browser blocked audio. Check that media volume is up and the car isn't muted.
Is it safe?
Set it up while parked, keep the volume at a level where you can still hear sirens and traffic, and follow local laws on in-car audio.