Heard about Apple Watch Series 3 "LTE problems"? It's actually a bug with how Apple Watch uses Wi-Fi, and it's fixed in watchOS 4.0.1.

Update: October 4, 2017

Apple has pushed out an update to Apple Watch, watchOS 4.0.1, that fixes watchOS 4's LTE/Wi-Fi bug. From Apple's update notes:

watchOS 4.0.1 fixes issues that in rare cases were causing Apple Watch to join unauthenticated (captive) Wi-Fi networks, such as those found in public places like coffee shops and hotels, which direct the user to a web page before the network can be accessed.

To download the fix, visit the Watch app on your iPhone.

How the Apple Watch connects to Wi-Fi

Like your iPhone, your Apple Watch has a Wi-Fi antenna inside of it, which allows it to connect directly to Wi-Fi networks (or via your iPhone) rather than always using your cellular data.

Where the two devices differ is in how they can connect: The Apple Watch doesn't have an Auto-Join Wi-Fi screen, or a place to select networks. Nor does it have an option to dictate or Scribble in passwords. In short: Your Apple Watch can't connect to Wi-Fi unless your iPhone has first connected to it.

Essentially, when your iPhone connects to a Wi-Fi hotspot and enters in the password while you're also connected to Apple Watch, your iPhone syncs that information over to your Watch.

Apple Watch can then access that information and connect to a network — even if you visit that location in the future with only your watch. That way, you can use all of your Apple Watch's online capabilities in Wi-Fi areas (like Messages, Maps, and any third-party apps) whether you have a GPS + Cellular model or a Series 0 Apple Watch.

Sounds easy enough, right? Unfortunately, there are a few limitations.

Where Wi-Fi fails on Apple Watch

Because Apple Watch doesn't have the Wi-Fi chops of its paired sibling, it struggles with a few areas, as outlined in a Support article on Apple.com. Namely:

  • You won't be able to connect to a new Wi-Fi network unless your iPhone is present and can connect to it.
  • Your iPhone needs to be paired with Apple Watch when it connects to the network — it doesn't work over iCloud Keychain
  • Apple Watch can only use 802.11b/g/n 2.4GHz networks, not 5GHz networks.
  • Apple Watch shouldn't connect to any public network that has an interstitial captive, like a hotel login, Google Starbucks terms and conditions acceptance, or other subscription information

The watchOS 4 "LTE" bug, and its solution

A few early Apple Watch Series 3 GPS + Cellular reviewers noticed significant connection problems with their Apple Watch review units, prompting Apple to make a statement. From Lauren Goode at The Verge:

Eventually, the company issued an official statement, acknowledging the issue. "We have discovered that when Apple Watch Series 3 joins unauthenticated Wi-Fi networks without connectivity, it may at times prevent the watch from using cellular," an Apple spokesperson said in an emailed statement.

Essentially, the Series 3 GPS + Cellular watch tries to save battery life at all times by using your iPhone's connection — or failing that, a Wi-Fi network. Unforutnately, the watchOS 4 bug allowed the Apple Watch, in rare cases, to try and jump on a so-called "captive" network — a public network with an interstitial login prompt or terms and conditions agreement. (You've probably seen these at a Starbucks, McDonalds, or Panera.)

By default, the Apple Watch shouldn't be allowed to connect to captive networks at all, as there's no way for it to get through that interstitial layer. Unfortunately, there was a bug in watchOS 4.0 where captive networks were recognized as on par with normal saved Wi-Fi networks — allowing users to "connect" to a network they'd never actually be able to use the internet with.

The fix is now available, in the form of a watchOS software update — you can download it here:

How to download watchOS 4.0.1

In short: The "LTE" bug wasn't problem with the watch's Cellular service: It just happened to be an existing issue that became extremely relevant with the release of the Cellular + GPS watch. (It's also one of the reasons I've asked multiple times for a way to authenticate Wi-Fi networks locally on Apple Watch with dictation.) You can read more about how LTE works (and doesn't) on the watch below:

More info: How LTE works on the Apple Watch

How to tell if your Apple Watch is connected to Wi-Fi or cellular networks

When your Apple Watch connects to a Wi-Fi network instead of your iPhone or cellular, you'll see a different symbol when you swipe up on Control Center from the watch face: A green "Connected" cloud icon, or (Cellular model only) blue Wi-Fi bars.

Here, the Apple Watch is connected to Wi-Fi.

Here, the Apple Watch is actively connected to a cellular network.

Any other questions about Apple Watch and Wi-Fi?

Let us know below.