To run openpilot in your car today, you buy a comma four for $999, install the free openpilot software on it, and plug it into a supported car with the harness that comes in the box. Those are the terms on comma’s product page as of October 19, 2026. comma lists more than 350 supported cars, and you can return the device within 30 days for a refund.
If you searched for the comma 3X, the comma four is its replacement. comma says it has the same compute, cameras and functions as the 3X in a package one-fifth the size. The comma shop no longer sells the 3X itself, only accessories for it.
What openpilot does in your car
openpilot replaces the steering and speed control of your car’s built-in driver assistance. It keeps the car in its lane and manages speed and following distance on the road, using the comma device’s cameras and your car’s own controls. comma’s product page says it can drive for hours without intervention with the help of an attentive driver.
That last part is the condition. openpilot is driver assistance, not self-driving: you stay responsible and must watch the road. The device’s driver-facing camera monitors attention. In SAE terms this is Level 2, the same category as Tesla FSD (Supervised) and GM Super Cruise.
The software is open source under the MIT license and lives on GitHub. The current release is 0.11.1. comma says openpilot follows ISO 26262 guidelines, and the code that limits what openpilot can command runs on a separate safety chip (the “panda”) with its own tests.
What it costs
- comma four: $999, including a car harness for the car you select. Rush shipping in the US is free; international shipping is a $30 flat rate plus your own customs and taxes.
- Upgrading from an older comma device: comma gives a $250 credit for trading in any comma device in any condition. Because all comma devices use the same harness, you can also skip the new harness for $50 less. Together that’s the $699 price on the shop page.
- comma prime (optional): a subscription for cloud video storage and remote access. comma’s FAQ says you don’t need it for any core function. The comma four includes one free month and stores about 10 hours of footage on its 128 GB drive without it.
- Return and warranty: 30-day money-back trial from the delivery date ($9.99 is deducted if you use comma’s prepaid return label), and a 1-year hardware warranty.
Check that your car is supported
Start at comma’s supported vehicles page (last updated October 6, 2026). It lists 27 brands. A few things to know when you read it:
- Support is by model and year, and sometimes by trim. A 2022 Hyundai Ioniq 5 can be supported while another trim or year isn’t.
- The list refers to US-market cars unless it says otherwise. Some entries are marked for a single country.
- Toyota, Hyundai and Kia have the most entries (45, 45 and 42), followed by Honda (38) and Ford (25). comma’s own favorites include the Kia EV6, Hyundai Ioniq 5, Toyota Corolla 2020–22 and Ram 1500 2019–24.
- Tesla Model 3 and Model Y with HW3 or HW4 appear on the list. Rivian support covers the R1S and R1T from 2022 to 2024.
If your car isn’t there, comma adds cars with each openpilot release, and the vehicles page has a form to get an email when yours is added.
How setup works
- Order the comma four and select your car, so the right harness ships with it.
- Follow comma’s setup guide. comma says installation takes about 15 minutes: the harness connects behind the camera trim at the top of the windshield, and the device mounts to the glass with 3M tape.
- On first start, the device asks for a software URL. The comma four ships without driving software. Enter openpilot.comma.ai to install the official release. (openpilot-test.comma.ai is a staging branch that gets releases slightly early; the nightly branches aren’t meant to be stable.)
- Pair the device in comma connect if you want to see your drives or start the free prime month.
Installing doesn’t permanently modify the car; unplugging it returns the car to stock. Check your state’s rules on windshield mounts before you install, since some states restrict objects on the windshield.
What it collects
By default, openpilot uploads driving data to comma’s servers: road-facing camera video, CAN bus data, GPS, motion sensors and system logs. comma uses it to train its models. The driver-facing camera and microphone are recorded only if you opt in, and you can turn off data collection. By using openpilot you grant comma a perpetual right to use the data, according to the openpilot README.
Can openpilot use a bigger GPU?
Yes, with a separate product. In August 2026 comma launched chestnut (from $249 on the shop page), a small adapter that turns USB into PCIe so a comma four can use a desktop graphics card to run larger openpilot models. openpilot has separate release branches for it. You don’t need it to run the standard release.
For how openpilot compares with car-maker systems, see Tesla FSD pricing and hardware in 2026 and Mercedes Drive Pilot, a Level 3 system.