HTML Formatter and Validator

This tool formats and validates HTML input in a single pass. It accepts messy markup, normalizes whitespace, wraps long attributes, and standardizes indentation according to configured rules, producing clean, readable code. Simultaneously, it runs HTML5 compliance checks and compiles a structured report of errors and warnings. The dual output lets developers immediately see a corrected version and an issue map, enabling quick fixes and faster review cycles. It works on both small code samples and larger files, and results are reproducible across repeated runs with the same options.
Conceptually, the process builds a document tree from the input, then re-serializes it with a chosen style. The formatter emphasizes consistency (spaces versus tabs, 2- or 4-space indentation) and safeguards comments and doctype handling. The validator compares tags, attributes, nesting, and required constraints against the HTML5 specification, returning precise locations when possible. Use cases include cleaning CMS exports, preparing snippets for tutorials, and aligning markup with internal style guides.
Unique value lies in coupling formatting and validation in one workflow, reducing manual cleanup time and providing reproducible results suitable for automation. The tool supports configuration for indentation, attribute wrapping, and inclusion of the doctype, and it can emit outputs as plain text or as structured data for CI pipelines. Target audiences are developers, QA analysts, documentation teams, and content editors seeking reliable HTML quality. The approach prioritizes correctness and consistency without altering script or style semantics.
Typical scenarios include sanitizing user-generated templates, validating component samples before embedding in templates, and generating standards-compliant fragments for knowledge bases.