Validate HTML5 code with html5validator. Find errors and improve code quality. Quick validation with directory support and custom output formats. Free online tool, no registration required.

html5validator

Validate HTML5. More information: https://github.com/svenkreiss/html5validator.

  • Validate a specific file:

html5validator {{path/to/file}}

  • Validate all HTML files in a specific directory:

html5validator --root {{path/to/directory}}

  • Show warnings as well as errors:

html5validator --show-warnings {{path/to/file}}

  • Match multiple files using a glob pattern:

html5validator --root {{path/to/directory}} --match "{{*.html *.php}}"

  • Ignore specific directory names:

html5validator --root {{path/to/directory}} --blacklist "{{node_modules vendor}}"

  • Output the results in a specific format:

html5validator --format {{gnu|xml|json|text}} {{path/to/file}}

  • Output the log at a specific verbosity level:

html5validator --root {{path/to/directory}} --log {{debug|info|warning}}