How to Test on iOS Simulators (Including iOS 11.3) With TestMu AI

How to Install and Run Older iOS Simulators (Including Legacy Versions)

iOS 11.3 is long superseded, but the need to test on older iOS versions never goes away. Some users are slow to upgrade, and regressions often surface only on legacy runtimes. Here is how to get older simulators running.

Using Xcode. In a modern Xcode, open Settings, go to the Platforms tab, and download the iOS runtime you need. Each runtime is a separate simulator SDK that Xcode installs alongside the current one.

Using the command line. You can also download runtimes with xcodebuild:

# List and download the iOS platform and its runtimes
xcodebuild -downloadPlatform iOS

# Download a specific older iOS runtime
xcodebuild -downloadPlatform iOS -buildVersion 11.3

The catch is that Apple stops supporting very old runtimes on current macOS versions, so a runtime like iOS 11.3 may simply refuse to install on a new Mac. This is exactly where a cloud testing platform helps: TestMu AI gives you instant access to a wide range of iOS versions and real devices from the browser, with no local Xcode setup, runtime downloads, or macOS-version conflicts to manage.

Essential Command-Line Operations for iOS Simulator Testing (simctl)

Once a simulator runtime is installed, xcrun simctl is the tool for driving simulators from the terminal, which is essential for CI and scripting. The core commands are:

# List all available simulators and their state
xcrun simctl list devices

# Boot a specific simulator by name or UDID
xcrun simctl boot "iPhone 15"

# Install an app build (.app) onto the booted simulator
xcrun simctl install booted /path/to/YourApp.app

# Launch the installed app by its bundle identifier
xcrun simctl launch booted com.yourcompany.YourApp

Note that simctl installs .app bundles built for the simulator; a distribution .ipa built for real devices will not run on a simulator. Using "booted" as the target applies the command to whichever simulator is currently running.

Advanced Simulator Testing: Deep Links, Location, and Push Notifications

simctl also handles the scenarios that are otherwise hard to trigger by hand:

# Open a universal link or custom deep link in the app
xcrun simctl openurl booted "https://example.com/products/42"

# Simulate a custom GPS location (latitude,longitude)
xcrun simctl location booted set 37.7749,-122.4194

# Send a mock push notification from an APNS payload file
xcrun simctl push booted com.yourcompany.YourApp payload.apns

With openurl you can confirm that universal links and deep links route to the correct screen. The location command feeds custom coordinates to test maps and geofencing, and simctl push delivers a simulated APNS notification from a JSON payload file, so you can test notification handling without a real push server.

Local Xcode Simulator vs Cloud Simulator

Local simulators are great for day-to-day development, but they have limits that a cloud platform removes. Here is how they compare: