Free tool
HTML Validator
Check your HTML code for errors and ensure it follows web standards. Catch problems before your visitors do.
Validation features
Standards compliance
Check your HTML against W3C web standards
Error detection
Find syntax errors, missing tags, and invalid attributes
Warnings and suggestions
Get recommendations for improving your markup
Line-by-line feedback
See exactly where each issue occurs in your code
What we check
+Tag matching
+Attribute validity
+Nesting rules
+DOCTYPE declaration
+Character encoding
+Required elements
+Deprecated tags
+Accessibility basics
How validation works
Validate your code in 3 steps
Drop files here
my-file
1. Submit your HTML
Upload a file, paste code, or enter a URL to validate.
your-project
.bopbee.com
Custom domain
Password
2. Review results
See errors and warnings with line numbers and explanations.
your-project
DEPLOY
3. Fix and revalidate
Make corrections and run validation again until your code is clean.