Web forms are the standard way for to obtain input data of the users. As usual, you always need to validate the input data before to accept them, so the server-side validation is necessary because errors in the input data can generate errors in the server code.
Parsleyjs
Parsley, the ultimate javascript form validation library.
jQuery Credit Card Validation Plugin Smart Validate
Smart Validate is a jQuery credit card validation plugin, that makes credit card format validation a simple task. It ensures that user has entered valid credit card number before making actual transaction.
Quick Validation
jquery-form-validator
Validations range from email, phone, url to more complex calls such as ajax processing. Bundled in several locales, the error prompts can be translated in the locale of your choice.
validator
The javascript validation code is based on jQuery. The Validator is cross-browser and will give you the power to use future-proof input types such as ‘tel’, ‘email’, ‘number’, ‘date’, and ‘url’. I can sum this as a ‘template’ for creating web forms.
validatr
Validatr will use native validation whereever possible, relying on a small piece of Modernizr to test for support. If an input type is not supported or a custom test is found Validatr will use it’s own ruleset to supplement native validation. In either case, the validation message is displayed in a cross-browser manner allowing for customization.
happyjs
Lightweight form validation for jQuery or Zepto.js.
jquery formvalidate
jQuery Form Validate is a jQuery plugin that helps validate your HTML forms. It takes validation rules from the HTML 5 data attributes applied to each input.
validity
jquery live form validation
Its a jQuery plugin which helps create easy form validations with high flexibility and a large set of options.
jval jquery form field validation plugin
jVal is a jQuery form field validation plugin that provides an appealing animated message flyout that doesn’t impede form layout/design while being user-friendly.
Moment.js
mailcheck.js
The Javascript library and jQuery plugin that suggests a right domain when your users misspell it in an email address.
validate.js
Lightweight JavaScript form validation library inspired by CodeIgniter. No dependencies, just over 1kb gzipped, and customizable!
jQuery.validity
US2FormValidator
This framework allows you to validate inputs of text fields and text views in a convenient way.
jqBootstapValidation
A JQuery validation framework for bootstrap forms.