Create a new app
Before creating a new Expo app, you have to make sure that:
- Expo CLI is installed on your development machine
- Expo Go app is installed on your iOS or Android physical device or emulator
If you have not installed any of these tools, go back to the Installation
guide before proceeding.
# Create a project named my-app
npx create-expo-app my-app
# Navigate to the project directory
Start the development server by running the following command:
When you run
), Expo CLI starts Metro Bundler
and serves it to the Expo app. Learn more about how Expo Development Server
To open the app:
- On your iPhone or iPad, open the default Apple "Camera" app and scan the QR code you see in the terminal.
- On your Android device, press "Scan QR Code" on the "Home" tab of the Expo Go app and scan the QR code you see in the terminal.
You can open the project on multiple devices simultaneously. Go ahead and try it on an iPhone and Android phone at the same time if you have both handy.
Is the app not loading on your device?
First, make sure you are on the same Wi-Fi network on your computer and your device.
If it still doesn't work, it may be due to the router configuration — this is common for public networks. You can work around this by choosing the "Tunnel" connection type when starting the development server, then scanning the QR code again.
Using the "Tunnel" connection type will make app reloads considerably slower than on "LAN" or "Local", so it's best to avoid tunnel when possible. You may want to install a simulator/emulator to speed up development if "Tunnel" is required for accessing your machine from another device on your network.
Using a simulator or emulator?
If you are using a simulator or emulator, you may find the following Expo CLI keyboard shortcuts to be useful to open the app on any of the following platforms:
Open App.js file in your code editor and change the text to "Hello, world!". You are going to see it update on your device. This is great progress! You now have the Expo toolchain running on your machine, can edit the source code for a project, and see the changes live on your device.
Are the changes not showing up on your device?
Expo Go is configured by default to automatically reload the app whenever a file is changed, but let's make sure to go over the steps to enable it in case somehow things aren't working.
Close the Expo app and reopen it.
Once the app is open again, shake your device to reveal the developer menu. If you are using an emulator, press Cmd ⌘ + D for iOS or Ctrl + M for Android.
If you see
Enable Fast Refresh, press it. If you see
Disable Fast Refresh, dismiss the developer menu. Now try making another change.