HTML Validator
Check that HTML tags are properly opened and closed, live as you type.
Every tag is properly opened and closed.
Checks that tags are balanced, live as you type. This is a structural check, not a full HTML5 spec validator (it won't catch every possible validity issue W3C's validator would). Runs entirely in your browser; nothing you type is sent anywhere.
What is HTML Validator?
Paste HTML and this tool checks that every tag is properly opened and closed, flagging any mismatch immediately — a quick way to catch a stray unclosed tag before it breaks a page's layout.
FAQ
No — this is a structural balance check (are tags properly nested), not a full HTML5 spec validator. It won't catch every issue the W3C validator would, like invalid attribute values or deprecated elements.
No, everything runs entirely in your browser.