HTML Tag Validator

This tool analyzes HTML input to confirm correct tag nesting, properly quoted attributes, and mandatory declarations such as the doctype. It is designed for developers, testers, and content teams seeking automatic checks that reduce rendering issues and accessibility problems. Conceptually, the tool tokenizes markup, builds a hierarchical tree, and flags violations with precise line and column locations. It supports strict and lenient modes to suit quick reviews or CI integrations, and can export structured JSON reports for further processing. Users benefit from faster debugging, improved consistency across codebases, and easier collaboration with non technical stakeholders through clear validation outputs. Core features include nested tag validation, doctype presence verification, attribute quote checks, and detailed error/warning lists. Use cases include local development validation before push, CI pipeline integration, and content workflow quality control. The tool differentiates itself by producing machine-readable error objects compatible with automation and by offering precise location data to accelerate fixes.