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Share the browser preview of a running Expo Simulators session, or build an authenticated expo.dev link that starts a new session from an EAS Build, fingerprint, archive, or Expo Go.

Expo Simulators is a limited-access preview. It is not included with paid or free plans and is currently available only to select partners. Join the waitlist if you are interested in trying it.

You can hand an Expo Simulators session to another person in two ways. Share a session that is already running, or give them a create session link that starts a new session when they open it. In both cases, the person uses the browser preview to see the device and, on iOS, to control it.

Share a running session

Every session type includes a browser preview. The start command prints the browser preview URL. In --json output, the URL is remoteConfig.webPreviewUrl, or remoteConfig.previewUrl for a web-preview-only session. The session page on expo.dev links to the same preview with Open preview:

https://expo.dev/accounts/<account>/projects/<project>/simulator-sessions/<session-id>

The session page on expo.dev shows an Open preview button that opens the browser preview in a new tab. Android support is still in development, so some features that work on iOS may not work on Android yet.

If you plan to share a session, set a maximum duration when you start it, so that it stops on its own:

To share a session that is already running, share the browser preview URL or session page URL that it already has. Tell the person when the session stops. Activity in the browser preview does not reset the idle timer, so use --max-duration-minutes, not --max-idle-time-minutes, to limit a session that a person controls. See How long an Expo Simulators session runs.

Open the browser preview URL in a desktop browser. Do not open it on the remote device, because it is a browser stream and not a deep link. For who can open the preview, see Expo Simulators security model.

Start a session from a link

A create session link starts a session from an EAS Build, build fingerprint, application archive, or Expo Go. The link opens the session's browser preview when the preview is ready. Use one to add an Expo Simulators action to a pull request, CI result, or an internal tool without integrating the REST API.

Create session links start browser-preview-only sessions. They do not provision agent-device, Appium, or Argent. Use EAS CLI or the REST API when you need a controller, a blank device, or custom duration and idle limits.

Create session links support Android and iOS. Android support is still in development. A link with platform=android, or with an archive URL that ends in .apk, starts an Android session and shows an in-development warning. An Android application archive must be an .apk.

Opening a create session link starts a new session without a confirmation step. The link is not idempotent: opening it again can create another session that consumes Expo Simulators usage. To avoid starting a new session, open the existing one from the project's Simulator sessions page and share its session page URL.

Construct the URL

Use the Expo account name and project slug in the URL:

https://expo.dev/accounts/<account>/projects/<project>/simulator-sessions/create?<parameters>

The person opening the link must sign in to an Expo account that can access the project. If they are signed out, expo.dev preserves the complete URL during authentication and starts the session after they sign in.

Choose an application source

Every create session link requires exactly one application source:

Do not include more than one application source. A link with more than one, such as buildId together with expoGo=true, shows a validation error and does not create a session. A link without an application source cannot create a session.

EAS treats an empty application source value, such as buildId=, as absent.

Add other parameters

URL-encode parameter values, especially nested URLs and values that contain spaces. Most programming languages provide a URL builder that handles this encoding. For example:

const url = new URL('https://expo.dev/accounts/acme/projects/my-app/simulator-sessions/create');

url.searchParams.set('buildFingerprint', 'FINGERPRINT_HASH');
url.searchParams.set('platform', 'ios');
url.searchParams.set('name', 'PR preview');
url.searchParams.set('deviceIdentifier', 'iPhone 17 Pro');
url.searchParams.append('launchArgs', '-UITestMode');
url.searchParams.append('launchArgs', '1');
url.searchParams.set('openUrl', 'myapp://profile/42');

console.log(url.toString());

Examples

Start a session from an EAS Build

https://expo.dev/accounts/acme/projects/my-app/simulator-sessions/create?buildId=BUILD_UUID

The build must be finished, and its artifact must not be expired. An iOS build must target the iOS Simulator instead of a physical iOS device. An Android build must be an APK.

Start the most recent installable build with a fingerprint

https://expo.dev/accounts/acme/projects/my-app/simulator-sessions/create?buildFingerprint=FINGERPRINT_HASH&platform=ios

EAS resolves the fingerprint to the most recent installable iOS Simulator build. If no installable build with this fingerprint exists, the link shows a validation error. Use buildId instead when you need to select one specific build.

Name the session and choose a device

https://expo.dev/accounts/acme/projects/my-app/simulator-sessions/create?buildId=BUILD_UUID&name=PR%20preview&deviceIdentifier=iPhone%2017%20Pro

Start a session from an application archive

https://expo.dev/accounts/acme/projects/my-app/simulator-sessions/create?applicationArchiveUrl=https%3A%2F%2Fcdn.example.com%2FMyApp.tar.gz&platform=ios

Pass launch arguments and open a deep link

https://expo.dev/accounts/acme/projects/my-app/simulator-sessions/create?buildId=BUILD_UUID&launchArgs=-UITestMode&launchArgs=1&openUrl=myapp%3A%2F%2Fprofile%2F42

Start Expo Go and load a project from Metro

https://expo.dev/accounts/acme/projects/my-app/simulator-sessions/create?expoGo=true&platform=ios&sdkVersion=58&openUrl=exp%3A%2F%2Fmetro.example.ngrok.dev

EAS installs the Expo Go release for the requested SDK version and opens the openUrl value in it. Omit sdkVersion to use the current Expo Go release. The remote simulator must be able to reach Metro. Start Metro with a public tunnel before you open the link:

For more information, see Test your project in Expo Go on a remote simulator.

If no Expo Go release is published for the requested SDK version, the link shows a validation error.

What happens when the link opens

After authentication, expo.dev validates the parameters and build, then creates the session. It shows the session's startup progress while reserving a simulator and preparing the browser preview. This can take about a minute. When the browser preview becomes available, expo.dev redirects to its browser preview.

To return to or share the same session without starting another one, open it from the project's Simulator sessions page. Its session page URL uses this format:

https://expo.dev/accounts/<account>/projects/<project>/simulator-sessions/<session-id>

Closing the page or navigating away does not cancel a session creation that the service already accepted, and it does not stop a running session. Stop the session when you finish so that it does not continue consuming usage.

If the parameters or build are invalid, expo.dev shows a Cannot start simulator session error instead. Common causes include:

• An unfinished or expired build
• An iOS device build
• A fingerprint or expoGo link without platform
• No installable build for a fingerprint
• An unsupported archive URL
• sdkVersion without expoGo=true
• An SDK version without a published Expo Go release
• More than one application source