FluentValidation is a popular .NET library offering a fluent, expressive interface for building strongly-typed validation rules. It supports modern .NET runtimes including .NET 8+, and integrates smoothly into .NET Core, Blazor, and other ecosystems. FluentValidation has adopted the Code of Conduct defined by the Contributor Covenant to clarify expected behavior in our community. For more information see the .NET Foundation Code of Conduct. A validation library for .NET that uses a fluent interface and lambda expressions for building strongly-typed validation rules.

Features

  • Fluent syntax for defining property validation rules (e.g., RuleFor, NotEmpty, EmailAddress)
  • Advanced features: RuleSets, cascade mode, conditional validation, collections (RuleForEach)
  • Dependency Injection support for validator classes
  • Asynchronous validation capabilities
  • Extensibility with custom validators, error codes, localization, state, severity settings
  • Integration with .NET Core and Blazor for model validation and UI enforcement

Project Samples

FluentValidation Screenshot 1

Project Activity

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Categories

Libraries

License

Apache License V2.0

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Additional Project Details

Programming Language

C#

Related Categories

C# Libraries

Registered

2025-08-14
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