Nu Html Checker vs W3C Markup Validation Service: catalog facts
 Nu Html Checker |  W3C Markup Validation Service |
|---|
|
Free Free to use on the W3C website. |
Free A free service run by the W3C. |
|
Web |
Web |
- Checks against current HTML conformance rules rather than old doctypes
- Accepts a URL, a file upload or pasted markup
|
- Validate by URL, file upload or direct input
- Choice of character encoding and document type
|
- Checks one document at a time
- Behavior is described as experimental and subject to change
|
- HTML5 validation is marked experimental
- Modern HTML is better served by the separate Nu Html Checker
|
|
Web application |
Web application |
|
Closed source |
Closed source |
|
License not stated |
License not stated |
|
No account needed |
No account needed |
|
Needs internet |
Needs internet |
Checked September 23, 2026 | Checked September 23, 2026 |
Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.
Copy comparison link
