Devices to capture (App Store requirements) Skill

Automated App Store Screenshots

Set up Fastlane Snapshot to automatically capture App Store screenshots across multiple devices and languages.

Pre-flight Checks

Fastlane installed: !fastlane --version 2>/dev/null | grep "fastlane " | head -1 || echo "✗ Not installed - run: brew install fastlane"
Fastfile exists: !ls fastlane/Fastfile 2>/dev/null && echo "✓ Found" || echo "✗ Not found - run /setup-fastlane first"
Existing Snapfile: !ls fastlane/Snapfile 2>/dev/null && echo "✓ Already configured" || echo "○ Not configured yet"
UI Test target: !find . -maxdepth 3 -name "*UITests*" -type d 2>/dev/null | head -1 || echo "○ No UI test target found"
Simulators available: !xcrun simctl list devices available | grep -E "iPhone|iPad" | head -3

Arguments: ${ARGUMENTS:-setup}

Why Automate Screenshots?

App Store requires screenshots for multiple device sizes. Manual capture means:

5+ device sizes × 5+ screenshots × N languages = hours of work
Risk of inconsistency between screenshots
Repeat everything for each app update

Snapshot automates this: run once, get all screenshots.

Step 1: Initialize Snapshot

fastlane snapshot init

This creates:

fastlane/Snapfile - Configuration file
fastlane/SnapshotHelper.swift - Helper for UI tests

Step 2: Configure Snapfile

Edit fastlane/Snapfile:

# Devices to capture (App Store requirements)
devices([
  "iPhone 15 Pro Max",      # 6.7" display (required)
  "iPhone 15 Pro",          # 6.1" display
  "iPhone SE (3rd generation)", # 4.7" display (if supporting older phones)
  "iPad Pro 13-inch (M4)",  # iPad screenshots (if universal app)
])

# Languages to capture
languages([
  "en-US",
  # "ja",      # Japanese
  # "de-DE",   # German
  # "fr-FR",   # French
  # "es-ES",   # Spanish
])

# UI Test scheme
scheme("YourAppUITests")

# Output directory
output_directory("./fastlane/screenshots")

# Clear old screenshots before capture
clear_previous_screenshots(true)

# Stop on first error (set false to continue despite failures)
stop_after_first_error(true)

# Dark mode variants (iOS 13+)
# dark_mode(true)

# Workspace or project (uncomment one)
# workspace("YourApp.xcworkspace")
# project("YourApp.xcodeproj")

Step 3: Add SnapshotHelper to UI Tests

Add SnapshotHelper.swift to your UI test target:
- Drag fastlane/SnapshotHelper.swift into Xcode
- Ensure it's added to your UITests target (not main app)
Import and configure in your UI test file:

import XCTest

class ScreenshotTests: XCTestCase {

    override func setUpWithError() throws {
        continueAfterFailure = false
        let app = XCUIApplication()
        setupSnapshot(app)  // Initialize snapshot
        app.launch()
    }

    func testTakeScreenshots() throws {
        let app = XCUIApplication()

        // Screenshot 1: Home screen
        snapshot("01_HomeScreen")

        // Navigate to feature and capture
        app.buttons["Feature"].tap()
        snapshot("02_FeatureScreen")

        // Screenshot with content
        app.textFields["Search"].tap()
        app.textFields["Search"].typeText("Example")
        snapshot("03_SearchResults")

        // Settings screen
        app.buttons["Settings"].tap()
        snapshot("04_Settings")

        // Any additional screens...
        snapshot("05_DetailView")
    }
}

Step 4: Run Snapshot

# Capture all screenshots
fastlane snapshot

# Specific device only
fastlane snapshot --devices "iPhone 15 Pro Max"

# Specific language only
fastlane snapshot --languages "en-US"

# Skip launch (use existing simulator state)
fastlane snapshot --skip_open_summary

Screenshots are saved to fastlane/screenshots/{language}/{device}/.

Step 5: Upload to App Store Connect

After capturing, upload with deliver:

# Upload screenshots only (no binary)
fastlane deliver --skip_binary_upload --skip_metadata

# Or use the screenshots lane from setup-fastlane
fastlane ios screenshots

App Store Screenshot Requirements (2024)

Required Device Sizes

| Display Size | Example Devices | Dimensions | |-------------|-----------------|------------| | 6.7" | iPhone 15 Pro Max, 14 Pro Max | 1290 × 2796 | | 6.5" | iPhone 15 Plus, 14 Plus, 11 Pro Max | 1284 × 2778 | | 5.5" | iPhone 8 Plus (legacy) | 1242 × 2208 | | 12.9" iPad | iPad Pro 12.9" | 2048 × 2732 |

Minimum: You need at least 6.7" or 6.5" iPhone screenshots. Other sizes can be auto-generated by App Store Connect.

Screenshot Count

Minimum: 1 per device size
Maximum: 10 per device size
Recommended: 5-6 highlighting key features

Optional: Frame Screenshots with Device Bezels

Add device frames around screenshots using frameit:

# Install frameit
brew install imagemagick

# Frame screenshots
fastlane frameit

# Silver device frames
fastlane frameit silver

Create fastlane/screenshots/Framefile.json for custom titles:

{
  "default": {
    "title": {
      "font": "./fonts/MyFont.ttf",
      "color": "#000000"
    },
    "background": "#FFFFFF",
    "padding": 50,
    "show_complete_frame": true
  }
}

Troubleshooting

"SnapshotHelper.swift not found"

Re-run fastlane snapshot init and add the helper to your UI test target.

"Unable to boot simulator"

Reset the simulator:

xcrun simctl shutdown all
xcrun simctl erase all

Screenshots are black/blank

Ensure setupSnapshot(app) is called before app.launch()
Add small delays if content loads asynchronously:

sleep(1)  // Wait for content
snapshot("01_HomeScreen")

"No matching device found"

Check available simulators:

xcrun simctl list devices available

Update Snapfile device names to match exactly.

UI test fails to find element

Use accessibility identifiers:

// In your app code
button.accessibilityIdentifier = "settingsButton"

// In UI test
app.buttons["settingsButton"].tap()

Integrate with Fastfile

Add a dedicated lane for screenshots:

lane :screenshots do
  snapshot(
    scheme: "YourAppUITests",
    devices: ["iPhone 15 Pro Max", "iPad Pro 13-inch (M4)"],
    languages: ["en-US"]
  )
  # Optional: frame screenshots
  # frameit(white: true)
end

lane :upload_screenshots do
  deliver(
    skip_binary_upload: true,
    skip_metadata: true,
    overwrite_screenshots: true
  )
end

Best Practices

Use sample data: Pre-populate app with attractive demo content
Consistent state: Reset app state before each test run
Accessibility IDs: More reliable than text matching
Handle async: Add waits for network content to load
Dark mode: Capture both light and dark variants
Localization: Test with actual translations, not placeholders
Landscape: Include landscape screenshots for iPad if relevant

Files Created

fastlane/
├── Snapfile                    # Snapshot configuration
├── SnapshotHelper.swift        # Helper for UI tests (copy to test target)
└── screenshots/
    ├── en-US/
    │   ├── iPhone 15 Pro Max/
    │   │   ├── 01_HomeScreen.png
    │   │   ├── 02_FeatureScreen.png
    │   │   └── ...
    │   └── iPad Pro 13-inch (M4)/
    │       └── ...
    └── ja/
        └── ...

Complete Workflow

# 1. Set up snapshot
fastlane snapshot init

# 2. Write UI tests with snapshot() calls

# 3. Capture screenshots
fastlane snapshot

# 4. Review screenshots in fastlane/screenshots/

# 5. Optional: add device frames
fastlane frameit

# 6. Upload to App Store Connect
fastlane deliver --skip_binary_upload --skip_metadata

Agent Skills: Devices to capture (App Store requirements)

Skill Files