FluentValidation 9.3.0-preview3

A validation library for .NET that uses a fluent interface to construct strongly-typed validation rules.

Showing the top 20 packages that depend on FluentValidation.

Packages Downloads
FluentValidation.AspNetCore
AspNetCore integration for FluentValidation
60
FluentValidation.AspNetCore
AspNetCore integration for FluentValidation
59
FluentValidation.AspNetCore
AspNetCore integration for FluentValidation
58
FluentValidation.DependencyInjectionExtensions
Dependency injection extensions for FluentValidation
57
FluentValidation.AspNetCore
AspNetCore integration for FluentValidation
56
FluentValidation.AspNetCore
AspNetCore integration for FluentValidation
55
FluentValidation.AspNetCore
AspNetCore integration for FluentValidation
54
FluentValidation.AspNetCore
AspNetCore integration for FluentValidation
53
FluentValidation.DependencyInjectionExtensions
Dependency injection extensions for FluentValidation
53

FluentValidation 9 is a major release. Please read the upgrade notes at https://docs.fluentvalidation.net/en/latest/upgrading-to-9.html

Changes in 9.3.0:

  • Improvements to LanguageManager's lazy loading of resources.
  • Deprecate IStringSource and its implementors. Use delegates instead.
  • CustomizeValidatorAttribute now works in Razor pages (netcore 3.1 and net 5.0 only)
  • RuleSetForClientSideMessagesAttribute now works in Razor pages (netcore 3.1 and net 5.0 only)

Changes in 9.2.2:

  • Fix one of the inheritance validator overloads not working correctly.

Changes in 9.2.1:

  • Add non-generic Add method to inheritance validator.
  • Updates to Persian translations.
  • Added Bengali translations.

Changes in 9.2.0:

  • Add inheritance validator
  • Performance improvements

Changes in 9.1.3:

  • Fix an issue with IncludeRulesNotInRuleSet not working correctly

Changes in 9.1.2:

  • Make the ValidationContext.ThrowOnFailures getter public.

Changes in 9.1.1:

  • Fix an incorrect deprecation message.

Changes in 9.1:

  • Make ruleset separator character splitting consistent
  • Transform now works with RuleForEach
  • Introduce constants for rulesets
  • Resolve issue when attempting to use asynchronous conditions in a synchornous validaiton run
  • Added asynchronous versions of the TestHelper methods.
  • Introduce CascadeMode.Stop and deprecate CascadeMode.StopOnFirstFailure to resolve confusion/abiguity about setting the cascade mode at validator-level (#1437)
  • RaiseValidationException can be overridden to customize the exception throwing process
  • Add new Validate extension methods that allow options to be configured using a strategy

Changes in 9.0.0:

  • Removed support for netstandard1.1 and netstandard1.6
  • Removed support for end-of-life .NET Core versions (2.2 and 3.0). LTS versions are supported (2.1 and 3.1)
  • Default email validation mode now uses the same logic as ASP.NET Core. Previous regex behaviour is opt-in.
  • TestHelper advanced mode now has more features (see https://docs.fluentvalidation.net/en/latest/testing.html#advanced-test-extensions)
  • Equal/NotEqual now perform ordinal comparison when used with string properties
  • Severity can now be set dynamically with a callback
  • Removed WithLocalizedMessage (WithMessage that takes a callback is the replacement)
  • Removed ResourceName from ValidationFailure
  • Removed ResourceName and ResourceType from IStringSource.
  • Removed SetCollectionValidator which was deprecated in 8.0
  • Additional overload of OnAnyFailure that can receive a collection of validation failures
  • Remove DisplayAttribute integration and reference to DataAnnotations.
  • ComparisonProperty placeholder is now formatted like PropertyName
  • Translations of default error messages into other languages are now lazily-loaded
  • Added Slovenian translations of default error messages.
  • Added Icelandic translations of default error messages.
  • Added WithMessageArgument to the test helpers.
  • Add additional overload of SetValidator that takes a Func that receives the current property value.
  • ASP.NET Core: FluentValidationModelValidatorProvider and FluentValidationModelValidator are now public.
  • Work around a bug in ASP.NET Core's integration testing components that can cause ConfigureServices to run multiple times.
  • SourceLink integration.
  • placeholder can now be accessed in child validators.
  • Additional ValidationException constructor that allows using both the default message and a custom one together.
  • ScalePrecisionValidator algorithm now matches SQL Server.
  • Additional overload of the When methods that contain the validation context.
  • Automatically scanned types can be excluded when calling RegisterValidatorsFromAssemblyContaining in ASP.NET Core projects.
  • New AutomaticValidationEnabled property for use in ASP.NET Core projects (defaults to true).

Full release notes can be found at https://github.com/FluentValidation/FluentValidation/blob/master/Changelog.txt

.NET Framework 4.6.1

  • No dependencies.

.NET 5.0

  • No dependencies.

.NET Standard 2.0

  • No dependencies.

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12.2.0 13 10/10/2026
12.1.1 70 12/12/2025
12.1.0 49 12/14/2025
12.0.0 53 12/12/2025
12.0.0-preview1 41 12/11/2025
11.12.0 53 12/14/2025
11.11.0 49 12/15/2025
11.10.0 44 12/18/2025
11.9.2 43 12/28/2025
11.9.1 37 12/11/2025
11.9.0 50 12/17/2025
11.8.1 35 12/28/2025
11.8.0 45 12/12/2025
11.7.1 50 12/15/2025
11.7.0 44 12/14/2025
11.6.0 46 12/13/2025
11.5.2 36 12/13/2025
11.5.1 35 12/12/2025
11.5.0 43 12/28/2025
11.4.0 43 12/28/2025
11.3.0 40 12/28/2025
11.2.2 44 12/13/2025
11.2.1 40 12/13/2025
11.2.0 32 12/25/2025
11.1.1 33 12/28/2025
11.1.0 32 12/22/2025
11.0.3 52 12/13/2025
11.0.2 38 12/14/2025
11.0.1 46 12/14/2025
11.0.0 43 12/27/2025
10.4.0 51 12/28/2025
10.3.6 44 12/21/2025
10.3.5 47 12/22/2025
10.3.4 32 12/18/2025
10.3.3 39 12/13/2025
10.3.1 48 12/28/2025
10.3.0 47 12/12/2025
10.2.3 41 12/11/2025
10.2.2 35 12/18/2025
10.2.1 40 12/11/2025
10.2.0 41 12/13/2025
10.1.0 41 12/28/2025
10.0.4 37 12/28/2025
9.5.4 41 12/18/2025
9.5.3 44 12/28/2025
9.5.2 7 09/30/2026
9.5.1 41 12/24/2025
9.5.0 36 12/13/2025
9.4.0 33 12/28/2025
9.3.0 37 12/28/2025
9.3.0-preview3 39 12/28/2025
9.3.0-preview2 41 12/28/2025
9.3.0-preview1 45 12/28/2025
9.2.2 46 12/14/2025
9.2.1 38 12/28/2025
9.2.0 54 12/20/2025
9.1.3 33 12/11/2025
9.1.2 42 12/13/2025
9.1.1 36 12/18/2025
9.1.0 38 12/20/2025
9.0.1 36 12/13/2025
9.0.0-preview5 36 12/23/2025
9.0.0-preview4 30 12/14/2025
9.0.0-preview3 42 12/18/2025
9.0.0-preview2 33 12/28/2025
9.0.0-preview1 35 12/28/2025
8.6.3 35 12/14/2025
8.6.2 30 12/25/2025
8.6.1 50 12/20/2025
8.6.0 44 12/15/2025
8.5.1 39 12/28/2025
8.5.0 40 12/14/2025
8.5.0-preview5 45 12/23/2025
8.5.0-preview4 32 12/13/2025
8.5.0-preview3 34 12/24/2025
8.5.0-preview2 38 12/18/2025
8.5.0-preview1 32 12/15/2025
8.4.0 47 12/16/2025
8.3.0 42 12/20/2025
8.2.3 32 12/20/2025
8.2.2 40 12/13/2025
8.2.1 44 12/20/2025
8.2.0 33 12/28/2025
8.1.3 35 12/20/2025
8.1.2 39 12/28/2025
8.1.1 35 12/28/2025
8.1.0 35 12/28/2025
8.1.0-preview2 39 12/28/2025
8.1.0-preview1 47 12/28/2025
8.0.101 43 12/14/2025
8.0.100 37 12/28/2025
8.0.0 31 12/13/2025
8.0.0-rc1 34 12/28/2025
8.0.0-preview4 33 12/22/2025
8.0.0-preview3 46 12/25/2025
8.0.0-preview2 36 12/28/2025
7.6.105 35 12/21/2025
7.6.104 42 12/24/2025
7.6.103 38 12/18/2025
7.6.102 38 12/15/2025
7.6.101 41 12/28/2025
7.6.100 33 12/13/2025
7.6.0 32 12/21/2025
7.6.0-preview1 42 12/14/2025
7.5.2 55 12/13/2025
7.5.1 30 12/20/2025
7.5.0 31 12/25/2025
7.4.0 37 01/03/2026
7.3.4 49 12/18/2025
7.3.3 41 12/28/2025
7.3.2 36 12/14/2025
7.3.1 35 12/15/2025
7.3.0 30 12/28/2025
7.3.0-beta3 36 12/28/2025
7.3.0-beta2 39 12/21/2025
7.3.0-beta1 41 12/28/2025
7.2.1 33 12/20/2025
7.2.0 46 12/28/2025
7.2.0-beta3 34 12/28/2025
7.2.0-beta2 42 12/28/2025
7.2.0-beta1 37 12/28/2025
7.1.1 33 12/15/2025
7.1.0 35 12/28/2025
7.1.0-beta1 41 12/18/2025
7.0.3 38 12/28/2025
7.0.2 35 12/28/2025
7.0.1 36 12/12/2025
7.0.0 36 12/14/2025
7.0.0-beta3 35 12/17/2025
7.0.0-beta2 43 12/24/2025
7.0.0-beta1 38 12/15/2025
6.4.1 33 12/20/2025
6.4.1-beta1 45 12/28/2025
6.4.0 49 12/18/2025
6.4.0-rc4 50 12/28/2025
6.4.0-rc3 36 12/28/2025
6.4.0-rc2 33 12/28/2025
6.4.0-rc1 45 12/28/2025
6.4.0-beta9 44 12/18/2025
6.4.0-beta8 39 12/28/2025
6.4.0-beta7 46 12/13/2025
6.4.0-beta6 42 12/13/2025
6.4.0-beta5 37 12/28/2025
6.4.0-beta4 47 12/28/2025
6.4.0-beta3 50 12/27/2025
6.4.0-beta2 39 12/28/2025
6.4.0-beta10 43 12/28/2025
6.4.0-beta1 44 12/13/2025
6.3.4-alpha 42 12/28/2025
6.3.3-alpha 42 12/23/2025
6.2.1 39 12/14/2025
6.2.1-beta1 36 12/28/2025
6.2.0 45 12/13/2025
6.2.0-beta1 43 12/28/2025
6.1.0 32 01/08/2026
6.0.2 40 12/14/2025
6.0.1 6 09/29/2026
6.0.0 39 12/14/2025
5.6.2 41 01/05/2026
5.6.1 34 12/14/2025
5.5.0 43 12/14/2025
5.4.0 38 01/12/2026
5.3.0 31 01/13/2026
5.2.0 45 12/14/2025
5.1.0 45 12/11/2025
5.0.0.1 30 12/28/2025
4.0.0.1 34 12/28/2025
4.0.0 6 09/29/2026
3.4.6 38 12/14/2025
3.4.0 42 12/14/2025
3.3.1 34 12/14/2025
3.2.0 44 12/14/2025
3.1.0 39 12/12/2025
3.0.0.1 40 12/12/2025
3.0.0 46 12/20/2025
2.0.0 48 12/29/2025
1.3.0 43 12/13/2025