FSDRadarCheck Controls > Software > Additional Vehicle Information: the "Autopilot computer" line shows the hardware. Roughly, Model S and X switched to AI4 (also called HW4) in early 2023, US-built Model Y around late May to June 2023, Model 3 with the 2024 refresh, and every Cybertruck has it.
AI4 cars run Tesla's main FSD (Supervised) version. HW3 cars run a reduced "v14 Lite" version, and Tesla has said HW3 cannot do the unsupervised driving it is developing. No HW3 upgrade program with a price or date has been announced.
The names: HW3, HW4, AI4
Tesla's driver-assistance computer has gone through several generations. HW3 (Tesla also calls it the "FSD Computer", and lately AI3) went into cars from 2019. HW4 arrived in 2023; Tesla now calls it AI4, and the two names mean the same hardware. AI4 also came with higher-resolution cameras (Not a Tesla App). Tesla has talked about an AI5 computer, but it is not in customer cars as of September 2026.
Hardware and software are separate. Every HW3 and AI4 car has the computer; only some had FSD (Supervised) bought for them. See how to tell if a Tesla has FSD for the software side.
How to check a specific car
- The car's screen (best). Go to Controls > Software, then tap Additional Vehicle Information. The Autopilot computer line shows the hardware version. This was added in a 2024 software update, so a car on current software shows it (Not a Tesla App). If you cannot sit in the car, ask the seller for a photo of this screen.
- The cameras. On AI4 cars, the forward cameras behind the windshield have a reddish tint, and the housing has two working lenses and one blank; HW3 cars show three dark lenses. It is a quick visual check at a viewing, not a substitute for the screen.
- Model, year and build date. Good enough to shortlist cars, not to decide. Tesla changed over factory by factory, and 2023 deliveries were mixed.
- Tesla's record. Tesla's data carries an Autopilot hardware code. Be careful: the code
$APH4means HW3, not HW4. Some online code lists get this wrong. See Tesla option codes for FSD.
Which cars got which computer
These are approximate US changeover points, compiled from owner reports and press coverage. When a car sits near a boundary, the screen is the only reliable answer.
| Model | HW3 | AI4 (HW4) |
|---|---|---|
| Model S and Model X | About April 2019 to early 2023 | From early 2023 |
| Model 3 | About April 2019 to the end of the pre-2024 design | 2024 refresh onward |
| Model Y | 2020 to about May/June 2023 (US builds) | From about late May 2023 (Fremont) and June 2023 (Austin) |
| Cybertruck | None | All |
Sources: Not a Tesla App's hardware guide and our own reading of Tesla's archived inventory data. Model S and X built before 2019 started life with older hardware; see the HW2 section below.
What each computer runs today
AI4: Tesla's main FSD (Supervised) branch, version 14.3.x in September 2026. New features arrive here first, and some, such as Automatic Collision Evasion, are not part of the HW3 version (Not a Tesla App).
HW3: Tesla began rolling out "FSD (Supervised) v14 Lite" to HW3 cars on June 29, 2026 (Electrek), after HW3 cars had stayed on v12.6 since early 2025. Model 3 and Model Y came first; the rollout to HW3 Model S and Model X started in September 2026 (Not a Tesla App). Lite brings many v14 improvements, but not every AI4 feature.
What Tesla has said about HW3's future, in its own words:
"Hardware 3 simply does not have the capability to achieve unsupervised FSD."
Elon Musk, Tesla earnings call, April 22, 2026, as reported by Electrek
On the same call Musk described something like "a discounted trade-in for cars that have AI4 hardware", and in July 2026 he talked about an upgrade to "the next generation AI board" without a date (Electrek, July 22, 2026). As of September 2026 no trade-in value, retrofit price or schedule has been published. Do not pay extra for an HW3 car on the promise of an upgrade.
Everything here is FSD (Supervised). On both computers it is a driver-assistance system: the driver must stay attentive and ready to take over. Unsupervised driving is not available in customer cars as of September 2026.
HW2 and HW2.5 cars
Model S and X from late 2016 to early 2019, and the earliest Model 3s, were built with HW2.0 or HW2.5. They cannot run current FSD (Supervised) without a computer swap. Tesla's support page says: "If you purchased Full Self-Driving (Supervised) and have computer 2.0 or 2.5, you are eligible for a complimentary upgrade to the Full Self-Driving computer 3.0" (Tesla, AI computer installations, May 2026 capture). It gives no deadline and does not say whether a second owner qualifies. Many of these cars were upgraded years ago; the Autopilot computer line on the screen tells you. Model S and X built before late 2016 have first-generation Autopilot and cannot run FSD at all.
HW3 and AI4 at a glance
| As of September 2026 | HW3 | AI4 (HW4) |
|---|---|---|
| FSD (Supervised) version | v14 Lite (v14.2 Lite rolling out) | Main branch, v14.3.x |
| Newest features | Later, or not at all | First |
| Unsupervised driving | Tesla says HW3 cannot do it | Tesla says it is planned for AI4; not available in customer cars |
| Upgrade path | Talked about, no price or date | Not needed today |
| Cameras | Older, lower resolution | Newer, higher resolution |
| Typical cars | 2019 to early 2023 S/X, 2019 to 2023 Model 3, 2020 to mid-2023 Model Y | Newer S/X, 2024+ Model 3, mid-2023+ Model Y, Cybertruck |
Owned FSD on HW3 or a subscription on AI4?
This is the choice many buyers end up with, because older cars are more likely to have owned FSD and newer cars are more likely to have AI4. There is no single right answer, but you can frame it with numbers you can check:
- HW3 with owned FSD: no monthly fee, the Lite version today, and an uncertain upgrade story. Usually the cheaper car.
- AI4 without owned FSD: the main version, at $99 a month (about $1,188 a year) whenever you want it, on a newer and usually more expensive car.
If you would use FSD (Supervised) most months and are happy with what Lite does on a test drive, owned FSD on HW3 saves real money. If you want the newest features, or only use FSD on trips, an AI4 car with a subscription for the months you need may fit better. Try Lite on a test drive before you decide: it is the product you are buying, and it has changed a lot in 2026.
What it means when you are buying
- Owned FSD on HW3 still has value. You get v14 Lite today with no monthly fee. You are paying for what it does now, not for promises.
- Owned FSD on AI4 gets the main version. That is why sellers tend to ask more for these cars. We have not seen a published, well-sourced figure for how much more, so we do not quote one.
- An AI4 car without owned FSD can run the main version on a subscription, $99 a month in the US as of September 2026. Compare that against the premium for an owned-FSD car in what FSD adds to a used Tesla's value.
- Check the screen, not the listing. Sellers often guess the hardware from the year. A photo of the Additional Vehicle Information screen settles it.
FSD Radar is independent and not affiliated with Tesla, Inc. Facts in this guide are dated where they change often; we re-check Tesla's support pages regularly. Spotted something out of date? Email info@fsdradar.com.