Main features
Conformance checking
Valid markup is the foundation of a reliable web. Markuplint checks your HTML against the HTML Standard, WAI-ARIA, and other specifications โ catching errors that browsers silently ignore but assistive technologies and search engines may not.
On Your House Rules
Enforce your project's coding standards beyond what specs require. Configure rules for accessibility, security, performance, and naming conventions โ making your team's agreements machine-checkable.
For Designed Structures
Validate that components are used correctly within your design system. Markuplint checks attributes, properties, and parent-child relationships of elements โ keeping your component contracts intact.
Applying by selector
Apply rules to specific elements using CSS Selectors, extended pseudo-classes, or Regular Expressions. Fine-tune which rules apply where โ enforce strict rules in one section while relaxing them in another.
Beyond HTML
Lint JSX (React), Vue, Svelte, Astro, Alpine.js, HTMX, Pug, PHP, Smarty, eRuby, EJS, Mustache/Handlebars, Nunjucks, Liquid, Markdown, MDX, and Tagged Template Literals (lit-html) โ all through official parser plugins.
VS Code Extension
Get real-time feedback as you type with the Markuplint Extension for Visual Studio Code. No project setup required โ install the extension, open an HTML file, and start linting immediately.