iOS and Android Device Logs
Complete guide to viewing and filtering device logs on iOS and Android.
When to Use This Skill
- User needs to see device logs
- User is debugging crashes
- User wants to filter logs by app
- User needs real-time log streaming
- User asks "how to see logs"
Quick Commands
iOS Logs
Method 1: Console.app (GUI)
- Open Console.app (Applications > Utilities)
- Select your device in sidebar
- Click "Start Streaming"
- Use search to filter:
- By process:
process:YourApp - By subsystem:
subsystem:com.yourapp - By message:
"error"
- By process:
Method 2: devicectl (CLI - Recommended)
Method 3: simctl for Simulators
Method 4: Xcode Device Logs
- Window > Devices and Simulators
- Select device
- Click "Open Console"
- Or: View device logs for crash reports
iOS Log Predicate Examples
iOS Log Levels
Android Logs
Method 1: adb logcat (CLI)
Method 2: Android Studio Logcat (GUI)
- View > Tool Windows > Logcat
- Use filter dropdown:
- Package:
package:com.yourapp - Tag:
tag:MyPlugin - Level:
level:error
- Package:
- Create saved filters for quick access
Method 3: pidcat (Better CLI Tool)
Android Log Priority Levels
adb logcat Format Options
Common Android Filters
Viewing Crash Logs
iOS Crash Logs
Android Crash Logs
MCP Integration
Use MCP tools to fetch logs programmatically:
Log Parsing Tips
Extract JavaScript Errors
Filter Network Requests
Monitor Memory
Troubleshooting
Issue: No Logs Showing
iOS:
- Ensure device is trusted: Xcode > Window > Devices
- Try restarting log stream
- Check Console.app filters
Android:
- Enable USB debugging
- Run
adb devicesto verify connection - Try
adb kill-server && adb start-server
Issue: Too Many Logs
Use filters:
Issue: Missing Debug Logs
iOS: Debug logs are hidden by default
Android: Ensure log level is set correctly
Best Practices
- Use structured logging - Include context in log messages
- Add timestamps - Helps correlate events
- Filter early - Don't stream all logs
- Save important logs - Redirect to file for later analysis
- Use log levels appropriately - Debug for dev, error for production
Resources
- iOS Unified Logging: https://developer.apple.com/documentation/os/logging
- Android Logcat: https://developer.android.com/studio/debug/logcat
- devicectl Reference: https://developer.apple.com/documentation/devicemanagement


