ASP.NET - Precompiled Views

Precompiled views in ASP.NET are views that are compiled at build time instead of runtime. This means the view files are converted into compiled assemblies before the application is deployed, reducing work during application startup and first request execution.

Why Precompiled Views Are Used

Normally, Razor views are compiled the first time they are requested, which can cause a delay on the first page load. Precompiling views removes this delay by shifting the compilation step to build time. This improves performance and provides faster response times, especially in production environments.

How Precompiled Views Work Conceptually

During the build or publish process, Razor view files are compiled into a DLL. At runtime, the application loads these compiled views directly instead of parsing and compiling .cshtml files. As a result, the server skips view compilation and focuses only on rendering.

Impact on Application Startup and Performance

Precompiled views reduce startup overhead and eliminate first-request latency. This is particularly beneficial for large applications with many views or for systems where consistent performance is critical, such as high-traffic websites and enterprise applications.

Error Detection at Build Time

One major advantage is early error detection. Syntax errors, missing models or invalid expressions inside views are caught during build instead of appearing as runtime errors. This improves reliability and reduces production issues.

Deployment and Security Benefits

When views are precompiled, the original .cshtml files do not need to be deployed. This reduces deployment size and prevents exposure of view source code on the server. It also simplifies deployment because fewer files are required.

When Precompiled Views Are Most Useful

Precompiled views are ideal for production environments where performance, stability and predictable behavior matter. During development, runtime compilation may still be preferred for faster iteration, but precompilation is recommended before final deployment.