Apple Watch Series 12 and Apple Watch Ultra 4 connect over Wi-Fi 4 (802.11n) and Bluetooth 5.3, according to Apple’s tech specs, while the iPhone 18 Pro announced the same day has Wi-Fi 7 (802.11be) and Bluetooth 6. Apple has not explained the gap, but its compare page shows the watch radios are unchanged from Series 11, Ultra 3 and SE 3, and the one wireless chip the watch shares with the new iPhones is the second-generation Ultra Wideband chip.
In practice the difference matters less than the version numbers suggest. AirPods 5 and AirPods Pro 3 are Bluetooth 5.3 devices too, and the features Apple says the watch does over Wi-Fi and cellular, such as Workout Buddy without an iPhone, do not depend on Wi-Fi 7.
Key facts: the radios in Apple’s new devices
| Device | Wi-Fi | Bluetooth | Ultra Wideband | Other |
|---|---|---|---|---|
| Apple Watch Series 12 | Wi-Fi 4 (802.11n), 2.4 GHz and 5 GHz | 5.3 | Second generation | 5G RedCap and LTE on cellular models |
| Apple Watch Ultra 4 | 802.11n, 2.4 GHz and 5 GHz | 5.3 | Second generation | 5G and LTE, satellite |
| iPhone 18 Pro | Wi-Fi 7 (802.11be), 2×2 MIMO | 6 | Second generation | Apple C2 modem, N1 chip, Thread, NFC |
| AirPods 5 | None | 5.3 | None | H2 chip |
| AirPods Pro 3 | None | 5.3 | Second generation (case) | H2 chip |
Unchanged from Series 11, Ultra 3 and SE 3
Apple’s compare page lists the same connectivity row for all five current watches: 802.11n Wi-Fi, Bluetooth 5.3 and a second-generation Ultra Wideband chip. The Ultra 3 tech specs give Wi-Fi 4 and Bluetooth 5.3 as well. So the S11 chip in Series 12 and Ultra 4 changed the heart sensors, the Neural Engine and the Secure Exclave, but not the radios.
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Cellular models are the same story. Series 12’s tech specs say the cellular models support RedCap for 5G and LTE, across a long list of FDD and TDD 5G NR and LTE bands, and Apple listed 5G on cellular Series 11 last year. Ultra 4 has 5G and LTE built in, plus Emergency SOS, Messages and Find My via satellite, which Series 12 does not have.
What the watch actually does over Wi-Fi and cellular
Apple’s watchOS 27 page gives the clearest picture of what the watch radios are for. Workout Buddy now works without a nearby iPhone over Wi-Fi or cellular, and adds Spanish. Apple Watch For Your Kids can be set up without an iPhone. Siri AI, which Apple describes as a conversational assistant with personal context that can take action across apps, arrives on the watch in English on September 14.
Series 12’s specs also list Apple Pay, GymKit and international roaming on cellular models. None of these is a bandwidth-heavy task in the way a 4K video transfer on an iPhone is, and Apple’s watch pages make no throughput claims at all.
Bluetooth 5.3 and your AirPods
The Bluetooth number is the one people notice, because iPhone 18 Pro and iPhone Duo both list Bluetooth 6 and the watch does not. But Apple’s AirPods specs list AirPods 5, AirPods 5 with Wireless Charging Case, AirPods 4 and AirPods Pro 3 at Bluetooth 5.3, so the watch and every current AirPods model are on the same version. Apple has not published any feature that requires Bluetooth 6 between a watch and headphones.
The watch features that do involve AirPods, such as Live Translation and hands-free Siri AI, are listed by Apple as needing an Apple Intelligence iPhone and the latest software, not a particular Bluetooth version.
Ultra Wideband is the radio that matches
The second-generation Ultra Wideband chip is in Series 12, Ultra 4, iPhone 18 Pro and iPhone Duo, according to Apple’s specs. Apple’s watchOS 27 page lists a streamlined, map-centric Find My app that combines Devices, People and Items, and the AirPods Pro 3 case also carries a second-generation UWB chip. Ultra 4 pairs that with precision dual-frequency GPS; Series 12 uses precision L1 GPS.
What Apple has not said
- Why the watch stays on Wi-Fi 4 and Bluetooth 5.3 while the iPhones move to Wi-Fi 7 and Bluetooth 6. Apple’s pages give the specs without comment.
- Any Wi-Fi or Bluetooth throughput or range figures for Series 12 or Ultra 4.
- Whether the watch supports Thread, which Apple lists for iPhone 18 Pro’s N1 chip and for iPhone Duo but not on the watch spec pages.
- Which wireless chip is inside the watch. Apple names the N1 for iPhone 18 Pro but no equivalent for Series 12 or Ultra 4.
Series 12 and Ultra 4 arrive in stores Friday, September 18, and watchOS 27 ships as a free update on Monday, September 14 for Series 9 and later, SE 3 and Ultra 2 and later, paired with an iPhone 11 or later running iOS 27. If you are pairing a new watch with a new iPhone 18 Pro, the radios that talk to each other are Bluetooth 5.3 on the watch side and second-generation Ultra Wideband on both.
