You Scanned the QR Code but Expo Go Won't Open — Check the Terminal and the App Logins, in That Order

I was reading Expo's changelog one morning when a single sentence made me stop. To open a project in development, Expo Go now expects you to be logged in to the Expo CLI running in your terminal and to the Expo Go app on your phone — both.

If you used to scan a QR code and be inside your app a second later, this can feel like it came out of nowhere. If you scanned and nothing moved, or you were asked to sign in, this is the order I'd check things in.

One honest caveat: I did not reproduce this on my own iPhone. What follows comes from Expo's changelog entry dated September 3, 2026 and its documented steps, rearranged into a sequence that avoids guessing. Where I could not confirm something, I say so.

How to tell it's this

According to the changelog, the requirement applies to the latest iOS version of Expo Go. Simulator builds are not affected, and Android is described as "coming later." Development builds don't need a login at all.

So suspect it when:

• you scanned the QR code from npx expo start with your iPhone camera and Expo Go
• the same project opened fine before, and now it doesn't (or you're asked to sign in)
• you didn't touch the code

The changelog doesn't quote an error message. It does say Expo Go will tell you whether the login is missing in the terminal, in the app, or in both. Read that prompt first.

The order to check

There are only two places to look, then a comparison.

For the terminal side:

# Prints your username when logged in
npx expo whoami
 
# If not, follow the link it gives you to sign in via the browser
npx expo login

If whoami prints a username, the terminal is fine. If not, run login and finish in the browser.

The fix

The documented steps are:

1. Run npx expo login in your terminal and sign in through the browser.
2. Open Expo Go on your iPhone, tap the avatar at the top right of Home, and sign in.
3. Make sure both are the same account.
4. Scan the QR code again, or tap the dev server address listed on the Home tab.

The step I'd underline is the third. As an indie developer I keep separate accounts, one for client work and one for personal apps, and it is easy to be logged in on both sides and still mismatched. Compare the username strings, not the look of the screen.

If you open Rork's QR code

For Rork Pro, the FAQ says to scan the QR code and open it in Expo Go. In that flow the terminal side is Rork's, so I couldn't confirm whether you ever need to run npx expo login yourself, and the FAQ doesn't mention a login step for the preview.

What I can say safely:

• Signing in to the Expo Go app now costs you nothing.
• If you export a Rork project and run npx expo start on your own computer, the terminal login applies to you.
• If it still won't open, try the next section before contacting anyone.

Fix the side the prompt points at first. If you change both at once, you won't know which one worked.

If it still won't open

Logging in doesn't solve everything. Check these next:

• Are the phone and the computer on the same Wi-Fi? Some office and school networks block device-to-device traffic.
• Is Expo Go up to date? An older build may not match your project's SDK version.
• Is your project's SDK version within what the installed Expo Go supports?

Expo describes Expo Go as a learning playground and points production work to development builds. With the login requirement added, it may be a good moment to think about when you'll move there.

One next step

Run npx expo whoami once today and jot down the name it prints. The next time something refuses to open, comparing that name with the one in Expo Go will narrow the cause down by half.

If you're weighing a USB-based route instead, I wrote down my decision points in how far you can stretch free Companion testing. And if Companion itself won't connect, there's a connection troubleshooting guide.

I run this check first whenever I start using a new tool, and I'd rather keep doing that.