Top 20 NuGet validation Packages

Poort80.Umbraco.Validation asp.net dataanotations in Umbraco
Validation tools for method parameters and more
Attributes for validation objects. Meant to compliment System.ComponentModel.DataAnnotations
description
description
BMSF Reactive Validation is a library for creating composable, reactive, asynchronous validators powered by ReactiveUI.
Straight forward and highly configurable validation for WPF applications.
Validators to validate and cleanup values in a secure way.
Implementations of ASP.NET Core Identity IPasswordValidators
Implementations of ASP.NET Core Identity IPasswordValidators that verify the provided password is not one of the most common passwords. Inspired by Discource and https://blog.codinghorror.com/password-rules-are-bullshit/
Validation specification package
Parameter guard extensions for .NET that checks that a parameter meets the requirements and throws an ArgumentException if it doesn't.
FluentValidation Extensions
Validation extensions for AspNetCore.
Common types and interfaces for validation
A parsing/validation library for various identifiers used in Czech Republic, e.g. IČO (identifier number for legal persons), rodné číslo (birth number), číslo účtu (bank account number).
Warm and fuzzy validations for your objects.
Common functionality