How to Setup Caching on IIS

Cache Configuration

<configuration>
    <system.webServer>
        <staticContent>
            <clientCache cacheControlMode="UseMaxAge" 
                         cacheControlMaxAge="365.00:00:00" />
        </staticContent>
    </system.webServer>
</configuration>

Key settings explained:

• cacheControlMode: Defines how cache headers are set
• cacheControlMaxAge: Sets the maximum age for cached content
• staticContent: Configures caching for static files

Advanced Cache Control

<configuration>
    <location path="static">
        <system.webServer>
            <httpProtocol>
                <customHeaders>
                    <add name="Cache-Control" 
                         value="public, max-age=31536000, immutable" />
                </customHeaders>
            </httpProtocol>
        </system.webServer>
    </location>

    <location path="api">
        <system.webServer>
            <httpProtocol>
                <customHeaders>
                    <add name="Cache-Control" 
                         value="no-store, no-cache, must-revalidate" />
                    <add name="Pragma" value="no-cache" />
                </customHeaders>
            </httpProtocol>
        </system.webServer>
    </location>
</configuration>

<configuration>
    <system.webServer>
        <urlCompression doStaticCompression="true" 
                        doDynamicCompression="true" />
        <httpCompression>
            <staticTypes>
                <add mimeType="text/*" enabled="true" />
                <add mimeType="application/javascript" enabled="true" />
                <add mimeType="application/json" enabled="true" />
                <add mimeType="application/xml" enabled="true" />
                <add mimeType="image/svg+xml" enabled="true" />
            </staticTypes>
        </httpCompression>
    </system.webServer>
</configuration>

Compression settings explained:

• doStaticCompression: Enables compression for static files
• doDynamicCompression: Enables compression for dynamic content
• staticTypes: File types to compress

Generated Configuration

# IIS configuration will appear here

Recommended Practices

• Static Assets:
  • Use long cache times (1 year) with versioned URLs
  • Add Cache-Control: public for CDN caching
  • Enable compression for text-based assets
• Dynamic Content:
  • Use shorter cache times
  • Implement cache busting for updates
  • Consider using no-cache for user-specific content
• API Responses:
  • Use no-store for sensitive data
  • Implement ETag headers for validation
  • Consider using Vary header for different responses