Clean Language Validation

Providing special validation error building for has_many collection in Rails.

Use the familiar ActiveModel::Errors pattern for controller validations

Detects issuer from a number, has ActiveModel validations and translations support.

ActiveModel validation against duplicating records.

Uses dry-validation

Lightweight gem that utilizes Rails server-side model validations to display client-side error messages for Ajax form submissions.

Epic validator, wraps validation for HTML, JavaScript and CSS.

Simple way to do validations more clear :)

Adds a test that validates all your Rails fixtures.

Format and validation a URL in active record

Validations, except they don't do anything.

A simple js form validation

ENV var to Config object translation with validations.

Collection of validations and complex assertions

Provides validation and proper formatting for ISBN13 numbers.

IBAN rails validator with iso-iban.

Gem Utilities for ISBN validation and Isbn Conversion

iTunes Receipt validation

Json Schema Client is a Ruby client for JsonSchema with validation and hypermedia.