Lint HTML for missing DOCTYPE, unclosed tags, and unexpected closing tags. Paste your HTML and get instant feedback. Catch errors before browsers guess wrong — free, local, no signup.
Content reviewed October 2026 · About Toolzum
Validate CSS syntax — unclosed braces, bad properties, bad values — with line numbers. Catch the missing } breaking layouts — local validation, free, no signup.
Minify HTML by collapsing whitespace, stripping comments, and pruning optional tags. Slim landing pages for faster loads — local processing, free, no signup.
Validate package.json for required fields, semver format, and dependency presence. Catch missing fields and bad semver before installs fail — free, local, no signup.
Strip HTML to clean plain text for emails, docs, and analysis. Extract article text without tags — local conversion, free, no signup.
Play hangman with categories and difficulty levels — guess letters before parts run out. Six wrong guesses and it's over — free, local, no signup.
Missing DOCTYPE declaration, unclosed tags, unexpected closing tags, duplicate attributes, deprecated elements, and accessibility issues.
Yes. The linter checks HTML5 DOCTYPE, valid element nesting, required attributes, and semantic structure compliance.
No. The linter identifies issues with line numbers and descriptions. You must manually edit the HTML to fix reported problems.
Basic accessibility checks include missing alt attributes on images, missing form labels, and heading hierarchy issues.
No. All linting happens locally in your browser. No HTML data is transmitted.
7 tokens skip the open/close stack: br, hr, img, input, meta, link and !DOCTYPE (DOCTYPE presence itself is checked case-insensitively). Mismatches report Unexpected closing tag, leftovers report Unclosed tags with the tag list, clean docs print No issues found, and the toast counts findings as Found N issue(s).
Validator
Basic syntax sanity check for JSON (full parse), XML (root-element check), and YAML (real js-yaml parse) — JavaScript not included. Code never leaves your device.
HTML Formatter
Indents and structures HTML markup with proper nesting, attribute alignment, and readable indentation for templates and email designs.