Preferences vs SecureStorage in .NET MAUI

In .NET MAUI, Preferences and SecureStorage handle data persistence, but they serve very different security purposes.

1️⃣ Preferences (Unencrypted)

Best for light, non-sensitive data like UI themes, font sizes, or Last Login timestamps. It stores data in a simple Key-Value pair format.

Supported Types: bool, double, int, float, long, string, DateTime.

Storage Location:

• Android → SharedPreferences
• iOS → NSUserDefaults
• Windows → ApplicationDataContainer

Example:

// Saving data
Preferences.Default.Set("theme_color", "Dark");

// Retrieving data (with default)
string theme = Preferences.Default.Get("theme_color", "Light");

// Removing data
Preferences.Default.Remove("theme_color");
    

2️⃣ 🔒 SecureStorage (Encrypted)

Essential for sensitive information like Auth Tokens, Passwords, or API Keys. It encrypts data before saving it to the device's secure hardware.

Security Mechanisms:

• Android → Keystore
• iOS/macOS → Keychain
• Windows → Data Protection API

Limitation: Only supports string values. You must serialize objects (JSON) or convert numbers to strings.

Example:

// Saving a token
await SecureStorage.Default.SetAsync("oauth_token", "secret_value_123");

// Retrieving a token
string token = await SecureStorage.Default.GetAsync("oauth_token");

// Clearing all secure data
SecureStorage.Default.RemoveAll();
    

📊 Key Comparison

Feature	Preferences	SecureStorage
Security	None (Plain Text)	High (Encrypted)
Performance	Very Fast	Slightly Slower (Encryption overhead)
Async Support	Synchronous	Asynchronous (Task)
Best Use Case	User Settings	Authentication & PII

⚙️ Platform-Specific Requirements

• Android: To use SecureStorage, you must have Auto Backup configured correctly if you want data to persist across reinstalls.
• iOS: You may need to enable Keychain Sharing in your Entitlements.plist for certain scenarios.

🎯 Advanced Topics

• 🔄 JSON-serialize a User Profile into SecureStorage
• ⚙️ Unified Settings Wrapper class combining Preferences + SecureStorage
• 🔐 Biometric authentication guard before SecureStorage access

Preferences and SecureStorage in .NET MAUI — two APIs that let you persist data across app sessions.

⚙️ Preferences

Purpose → Store simple key-value pairs (like settings, flags, or user choices).

Storage Type → Non-sensitive data, saved in platform-specific storage:

• Android → SharedPreferences
• iOS/macOS → NSUserDefaults
• Windows → ApplicationDataContainer

Usage

using Microsoft.Maui.Storage;

// Save
Preferences.Set("theme", "dark");

// Retrieve
var theme = Preferences.Get("theme", "light"); // default = "light"

// Remove
Preferences.Remove("theme");

// Clear all
Preferences.Clear();
    

Best For → Settings, flags, app preferences, non-sensitive user data.

🔒 SecureStorage

Purpose → Store sensitive data securely (tokens, passwords, API keys).

Storage Type → Encrypted storage provided by the OS:

• Android → KeyStore
• iOS/macOS → Keychain
• Windows → Credential Locker

Usage

using Microsoft.Maui.Storage;

// Save securely
await SecureStorage.SetAsync("auth_token", "12345");

// Retrieve securely
var token = await SecureStorage.GetAsync("auth_token");

// Remove
SecureStorage.Remove("auth_token");
    

Best For → Authentication tokens, credentials, sensitive app data.

📊 Comparison Table

Feature	Preferences	SecureStorage
Data type	Key-value pairs	Key-value pairs
Security	Plain storage	Encrypted storage
Use case	Non-sensitive settings	Sensitive data (tokens, passwords)
Platform store	SharedPreferences / NSUserDefaults / AppDataContainer	KeyStore / Keychain / Credential Locker

💡 Best Practices

• Use Preferences for lightweight, non-sensitive data (like theme, language).
• Use SecureStorage for sensitive data (like login tokens).
• Always check availability of SecureStorage (some devices may restrict it).
• Handle exceptions gracefully (e.g., when storage is unavailable).