Running an Expo SDK 57 app in Expo Go? You now need to be logged in on both ends

You scan the QR code like you've done a hundred times before, npx expo start is running, the terminal looks fine, but the app on your phone just sits there with an error instead of loading your project.

Here's what changed: Expo Go on iOS has been updated in the App Store to support Expo SDK 57, and along with that update comes a new requirement. To run an SDK 57 project in development mode, you now need to be logged in to both the Expo CLI in your terminal and the Expo Go app itself, using the same account on both sides.

This is live now for the latest Expo Go on iOS. Android is getting the same treatment later, and it doesn't touch simulator builds or development builds at all.

What you'll see

If either side isn't logged in when you scan a QR code (or tap a dev server address on the Home tab), Expo Go shows you an error telling you exactly what's missing:

The message tells you whether the terminal needs a login, the app needs a login, or both. No guessing required.

How to fix it

On the terminal side, run:

npx expo login

and follow the link to sign in through your browser.

On the Expo Go app side, go to the Home tab, tap the avatar icon in the upper right corner, and enter your Expo username and password.

Once both are logged in with the same account, scan the QR code again (or tap the dev server address on Home) and your app should load normally.

The account has to match on both ends. Logging in as one user in the terminal and a different user in Expo Go won't work.

Limitations

A few things worth knowing before this trips you up:

• This currently only applies to the latest Expo Go for iOS. Android is coming, but isn't enforced yet.
• Simulator builds are exempt. This is specific to the physical Expo Go app.
• Development builds don't require login at all, this is an Expo Go-only change.

If you're on Android, it's still worth signing into Expo Go now rather than later. Being logged in automatically surfaces your running dev servers on the Home tab and lets you load published projects directly, so you're not scanning QR codes every time.

Where to start

• If you're hitting the login error right now: run npx expo login in your terminal, then log in through the avatar icon in Expo Go
• Make sure both logins use the same Expo account
• If you'd rather skip this entirely, switch to a development build, which doesn't require login

This post is based on content from the Expo blog. Follow @expo for more React Native content.