🔍 HTML Validator - Linter
Validate HTML against W3C standards and perform linting to assess code quality. Find missing tags, unbalanced elements, duplicate IDs, invalid attributes, and more. Supports HTML5, SVG 1.1, MathML 3.0, ITS 2.0, RDFa Lite 1.1.
HTML5
SVG 1.1
MathML 3.0
ITS 2.0
RDFa Lite 1.1
Option 1: Copy-paste
Copy-paste your HTML here
Paste any HTML document for validation
Option 2: Upload file
Or upload your HTML file
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Comprehensive HTML Validation & Linting
Missing Tags
Detects unclosed or unbalanced HTML tags
Duplicate IDs
Finds duplicate ID attributes
Invalid Attributes
Checks for invalid or deprecated attributes
Multiple Encodings
UTF-8, ISO, Windows encodings supported