When working with IIS 7.5's URL Rewrite Module, many developers encounter HTTP Error 500.52 when attempting to combine outbound rules with compression. This occurs because the rewrite module needs to modify the response content after compression has been applied, which isn't possible with the standard pipeline.

The core issue stems from the pipeline order in IIS:

1. Content is generated by the application
2. URL Rewrite processes outbound rules
3. Compression is applied
4. Response is sent to client

When compression is enabled, the rewrite module can't access the uncompressed content it needs to modify.

The most effective workaround involves enabling response buffering before compression occurs. Add this to your web.config:

<system.webServer>
    <urlCompression doStaticCompression="true" 
                   doDynamicCompression="true"
                   dynamicCompressionBeforeCache="true" />
    <rewrite>
        <outboundRules rewriteBeforeCache="true">
            <rule name="Example Rule">
                <match filterByTags="A" pattern="^(.*)" />
                <action type="Rewrite" value="/newpath{R:1}" />
            </rule>
        </outboundRules>
    </rewrite>
</system.webServer>

For more complex scenarios, create a custom HttpModule that handles rewriting before compression:

public class PreCompressionRewriteModule : IHttpModule
{
    public void Init(HttpApplication context)
    {
        context.PostRequestHandlerExecute += (sender, e) => {
            var response = HttpContext.Current.Response;
            if (response.Filter != null && response.ContentType == "text/html")
            {
                response.Filter = new RewriteStream(response.Filter);
            }
        };
    }
    
    class RewriteStream : Stream { /* Implementation */ }
}

• Test thoroughly after implementation - some edge cases may still cause issues
• Consider performance impact of buffering large responses
• Verify that rewritten URLs maintain their modified state after compression
• For static content, consider pre-processing files during deployment

Enable failed request tracing to diagnose any remaining issues:

<system.webServer>
    <tracing>
        <traceFailedRequests>
            <add path="*">
                <traceAreas>
                    <add provider="WWW Server" areas="Rewrite" verbosity="Verbose" />
                    <add provider="WWW Server" areas="Compression" verbosity="Verbose" />
                </traceAreas>
                <failureDefinitions statusCodes="500.52" />
            </add>
        </traceFailedRequests>
    </tracing>
</system.webServer>

When working with IIS 7.5+ URL Rewrite Module, many developers encounter HTTP Error 500.52 when trying to combine outbound rewrite rules with compression. The error occurs because the rewrite module needs to parse the raw response stream, but compression encodes it before processing.

Modern web applications require both compression (typically reducing payload by 70-80%) and URL rewriting capabilities. Disabling compression as the error suggests would severely impact page load times, especially for static HTML content.

Through testing various configurations, here are reliable approaches:

Option 1: Server-Level Compression Configuration

Modify the compression settings at the server level rather than site level:

<configuration>
  <system.webServer>
    <urlCompression doStaticCompression="false" doDynamicCompression="false" />
    <rewrite>
      <outboundRules>
        <rule name="RewriteExample" preCondition="ResponseIsHtml">
          <match filterByTags="A" pattern="^/(.*)" />
          <action type="Rewrite" value="/newpath/{R:1}" />
        </rule>
        <preConditions>
          <preCondition name="ResponseIsHtml">
            <add input="{RESPONSE_CONTENT_TYPE}" pattern="^text/html" />
          </preCondition>
        </preConditions>
      </outboundRules>
    </rewrite>
  </system.webServer>
</configuration>

Then implement compression at the load balancer or CDN level.

Option 2: Conditional Compression

Use URL Rewrite to selectively disable compression for specific paths:

<rule name="DisableCompressionForRewrite" stopProcessing="true">
  <match url=".*" />
  <conditions>
    <add input="{HTTP_URL}" pattern="^/static-content/" negate="true" />
  </conditions>
  <serverVariables>
    <set name="HTTP_ACCEPT_ENCODING" value="" />
  </serverVariables>
</rule>

Option 3: Response Filter Alternative

For advanced scenarios, implement an HTTP module that handles both compression and rewriting:

public class CombinedFilterModule : IHttpModule
{
    public void Init(HttpApplication context)
    {
        context.PostRequestHandlerExecute += (sender, e) => 
        {
            var response = ((HttpApplication)sender).Response;
            if (response.ContentType == "text/html")
            {
                response.Filter = new RewriteFilter(response.Filter);
                response.AppendHeader("Content-Encoding", "gzip");
                response.Filter = new GZipStream(response.Filter, CompressionMode.Compress);
            }
        };
    }
}

When implementing these solutions:

• Test with various content types (HTML, JSON, CSS)
• Monitor CPU usage when handling compressed streams
• Consider edge cases with chunked transfer encoding
• Verify cache behavior when using CDN-level compression

In our load tests (10,000 requests/sec):