How to use dark mode in simulator iOS 13?

Question

In Settings, scroll down to Developer and then Dark Appearance…

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Update

In addition to the above, there are now many other ways to enable dark appearance in the simulator, as shown in the many great answers below.

• Change Environment Overrides from Xcode (@AshCameron)

• Toggle Appearance ⇧⌘A from the Simulator menu (@Shredder2794)

• Update from the command line using xcrun simctl ui booted appearance … (@blackjacx, @tadija)

• Programmatically using overrideUserInterfaceStyle = .dark (@thisIsTheFoxe)

• Specify UIUserInterfaceStyle in your info.plist (@DhavalGevariya)

• Use SimGenie from Curtis Herbert…  https://simgenie.app

You can toggle the interface mode (i.e. Light / Dark) as well as adjust dynamic type setting on the fly (when the simulator is running) like this:

You can use the "Toggle Appearance" (ShiftCommandA) setting from the Simulator menu:

Simulator > Features > Toggle Appearance ⇧⌘A

Automated Appearance Change 🦉

Xcode 11.4 🌟

Apple released a powerful Xcode update which contains some useful things for this topic. Appearance can now be selected directly in the simulator. Just select Features > Toggle Appearance or ⇧+⌘+A. The automatic appearance switching could stil be important, e.g. for automated screenshot tests on the command line. The script becomes easy like this when using Xcode 11.4:

device_ids=("C741F3CD-FDAC-49EA-A4DB-7F797B97291E" "428183B6-3EB8-4D36-9938-9D07C141BF49")

# The value to use is now just 'dark' or 'light'
appearance=dark

for device in "${device_ids[@]}"; do
  xcrun simctl boot $device
  xcrun simctl ui $device appearance $appearance
done

No more simulator killing or re-setting needed which is a huge performance win. Also no fiddling around with any plist tools anymore - ever. keep in mind that you have to use device ids that are available in the runtime you use. Find them out using xcrun simctl list.

See also my complete script: https://github.com/Blackjacx/Scripts/blob/master/set-simulator-style.sh

Xcode 11.3

There is a way using the command line to switch a simulator between light and dark mode. If you have an array with your device IDs you can do the following:

device_ids=("C741F3CD-FDAC-49EA-A4DB-7F797B97291E" "428183B6-3EB8-4D36-9938-9D07C141BF49")

# Determine the plist value for the desired style: "dark" -> 2 / "light" -> 1
style=2

for device_id in "${device_ids[@]}"; do
  plist_path="${HOME}/Library/Developer/CoreSimulator/Devices/${device_id}/data/Library/Preferences/com.apple.uikitservices.userInterfaceStyleMode.plist"  
  printf '\n%s' "Set style $style for device $device_id ($plist_path)"

  killall "Simulator"
  xcrun simctl shutdown booted
  xcrun simctl erase $device_id

  # Crate the plist since it might not be available after erase
  [[ ! -f "$plist_path" ]] && /usr/libexec/PlistBuddy -c "save" $plist_path  
  # Set the style mode
  plutil -replace UserInterfaceStyleMode -integer $style $plist_path
done

If you want to specify device names in your script - since device IDs are different on different machines - you can also easily find the id's of them using the following bash code:

device_names=("iPhone SE" "iPhone 8" "iPhone 11 Pro" "iPhone 11 Pro Max")
device_ids=()

for name in "${device_names[@]}"; do
  id=$(xcrun simctl list --json | jq ".devices | .[] | .[] | select(.name == \"$name\") | .udid" | cut -d\" -f2)
  device_ids+=("$id")
done

printf '%s\n' "${device_ids[@]}"