midASP.NET
What are Filters in ASP.NET Core and how are they used?
Updated Apr 28, 2026
Short answer
Filters are components that run before or after controller actions.
Deep explanation
Filters allow executing logic at specific stages of the request pipeline. Types include Authorization, Action, Result, and Exception filters. They help in cross-cutting concerns like logging and validation.
Real-world example
Logging API requests or validating inputs before execution.
Common mistakes
- Using middleware instead of filters incorrectly.
Follow-up questions
- Difference between filters and middleware?
- What is ActionFilter?