Open-source alternatives to Validation

A simple filtering library for PHP

JSON Schema for PHP

Respect/Validation is a PHP validation library that operates on single input values through a fluent, chainable rule system. Each validator instance builds a linear constraint pipeline by appending rules to an internal stack, executing them sequentially and short-circuiting on the first failure. The library captures validation failures as structured exceptions, enabling callers to inspect detailed error metadata programmatically and respond with meaningful messages. The library distinguishes itself through its exception-based error handling model, which provides programmatic access to validat

A powerful schema validator!

PHP library - Validators for standards from ISO, International Finance, Public Administrations, GS1, Manufacturing Industry, Phone numbers & Zipcodes for many countries

Light and extendable schema validation library

Provides an object-oriented API to sanitize untrusted HTML input for safe insertion into a document's DOM.

Valitron is a simple, elegant, stand-alone validation library with NO dependencies