Tesla HW3 vs HW4: Differences and How to Tell Which You Have

HW4 (also called AI4) is Tesla's newer self-driving computer, with more processing power and higher-resolution cameras than HW3. HW4 cars get new FSD versions first and are what Tesla is targeting for unsupervised driving; HW3 cars still run FSD (Supervised) but trail behind. You can tell which you have in 30 seconds: open Controls > Software > Additional Vehicle Information on the touchscreen.

HW3 vs HW4 at a glance

How to check your hardware in the car

1. Touchscreen: tap Controls > Software > Additional Vehicle Information. It lists the Autopilot computer as AI3 (HW3) or AI4 (HW4).
2. Front cameras: from outside, look at the camera housing at the top of the windshield. HW4 cameras have red-tinted lenses; HW3 cameras look black.
3. Build date: printed on the label inside the driver's door jamb. Compare it with the switch dates below.

Which model years have HW4

The tricky year is 2023: Model S, Model X and Model Y all switched partway through, so a 2023 car could have either. Every 2023 Model 3 is HW3. For any specific car, the Hardware Checker above gives an instant answer.

What HW3 owners actually lose

• Timing: major FSD releases have reached HW4 first, with HW3 getting later or reduced versions.
• Unsupervised FSD: in 2026 Elon Musk said HW3 "simply does not have the capability" for unsupervised driving.
• Insurance savings: Lemonade's 50% FSD-mile discount requires HW4.
• Resale value: buyers who want FSD pay more for HW4 cars.

What you don't lose: HW3 cars still drive well with FSD (Supervised), get regular software updates, and keep every other Tesla feature.

Does HW3 still get FSD updates?

Yes, but behind HW4. Tesla has talked about trimmed-down FSD builds for HW3 to keep older cars improving. Expect new features to land on HW4 first and reach HW3 later, if at all.

Will Tesla upgrade HW3 to HW4?

Tesla has said owners who purchased FSD on HW3 will get a computer upgrade if it's needed for unsupervised FSD. In April 2026 it described replacing cameras, the computer and wiring at dedicated upgrade centers; by mid-2026 Musk suggested it might skip straight to a next-generation computer, with production around mid-2027. Subscribers aren't promised an upgrade. There's no paid HW3-to-HW4 retrofit you can book today.

On the October 2026 earnings call Tesla passed over the top-voted shareholder question on this, so the promise still has no date attached. Where unsupervised FSD actually stands tracks it each quarter.

Does it matter when buying used?

Yes, if you care about FSD:

• Want FSD long term? Pay a bit more for a HW4 car.
• Don't care about FSD? A HW3 car can be a great value — just don't pay an FSD premium for it.
• Buying a 2023 Model S, X or Y? Check the hardware on the car, not the listing.

Frequently asked questions

Is HW4 worth it over HW3?

If you'll use FSD, yes — HW4 gets new versions first and is Tesla's target for unsupervised driving. If you won't use FSD, HW3 is fine.

Can HW3 run FSD?

Yes, FSD (Supervised) runs on HW3, though newer versions reach it later or in reduced form.

Does the Tesla app show HW3 or HW4?

Not directly. Use the car's touchscreen (Controls > Software > Additional Vehicle Information) or check the front camera lenses.

Is there an HW4.5 or AI5?

Tesla has talked about an intermediate board and its next-generation AI5 computer, with production around 2027. No customer Tesla has AI5 as of late 2026.

The bottom line

HW4 is the hardware to have if FSD matters to you; HW3 still works but is falling behind. Check any car with the Tesla Hardware Checker before you buy — especially a 2023 model.