Validates the given string

Provides a clean DSL to validate params for controller actions.

Simple, powerful, and constraint-based validation

EachValidator that adds a parent model's association's validation errors to the parent model

Validates wether an association belongs to the same owner

The purpose of this gem is to validate countrycodes in ISO 3166-1 alpha-2 format

ActiveRecord callback which handle the name duplication in your model.

Validate iban

To prevent noobs from being uber noobs

ActiveModel validator that ensures Word-tags hasn't been accidentally pasted into WYSIWYG attributes.

This gem unions a server-side ActiveModel password strength validation plugin with a client-side password strength estimation

Validate specific value for Rails

Validate phone numbers against E.164 format with this Ruby on Rails gem

Validate against blacklist of words

Add to Rails the possibility to validate the quantity of an associate model

Validate Your Social Security Number

Add common validations.

Subdomain validator

This library helps validate that an attribute is a subset of a specified set

ValidatesTimeliness mongoid ORM compatability.