How to: Filtering, Sanitizing and Validation
*Libraries for filtering, sanitizing and validating data.*

* [Assert](https://github.com/beberlei/assert) - A validation library with a rich set of assertions. Supports assertion chaining and lazy assertions.
* [Aura.Filter](https://github.com/auraphp/Aura.Filter) - Provides tools to validate and sanitize objects and arrays.
* [CakePHP Validation](https://github.com/cakephp/validation) - Another validation library.
* [Filterus](https://github.com/ircmaxell/filterus) - A simple PHP filtering library.
* [HTML Purifier](https://github.com/ezyang/htmlpurifier) - A standards compliant HTML filter.
* [ISO-codes](https://github.com/ronanguilloux/IsoCodes) - A library for validating inputs according to standards from ISO, International Finance, Public Administrations, GS1, Book Industry, Phone numbers & Zipcodes for many countries.
* [JSON Schema](https://github.com/jsonrainbow/json-schema) - A [JSON Schema](https://json-schema.org/) validation library.
* [MetaYaml](https://github.com/romaricdrigon/MetaYaml) - A schema validation library that supports YAML, JSON and XML.
* [Respect Validation](https://github.com/Respect/Validation) - A simple validation library.
* [Symfony HTML Sanitizer](https://github.com/symfony/html-sanitizer) - An HTML sanitizer library.
* [Upload](https://github.com/brandonsavage/Upload) - A library for handling file uploads and validation.
* [Valitron](https://github.com/vlucas/valitron) - Another validation library.
* [Valinor](https://github.com/CuyZ/Valinor) - A library for mapping to strongly typed value objects.
* [Volan](https://github.com/serkin/Volan) - Another simplified validation library.