Operated by W3C. Last seen today.

What is W3C_Validator?


W3C_Validator is a developer helper operated by W3C. It's not currently classified as artificially intelligent or AI-related in any way. If you think this is incorrect or want to provide more detail, please contact us.


Developer Helper
Used by developers to test website functionality

Expected Behavior

Developer Helpers generally visit websites on direct behalf of a user who is evaluating some feature or attribute. Visits can be one-off or part of a larger crawl.

Access Control

Using Robots.txt

User Agent Token Description
W3C_Validator Should match instances of W3C_Validator

You can block W3C_Validator or limit its access by setting user agent token rules in your website's robots.txt.

# robots.txt
# This blocks W3C_Validator

User-agent: W3C_Validator
Disallow: /

Instead of editing your robots.txt manually, use the API or Wordpress plugin to keep your robots.txt up to date with the agent list automatically.

Get the Robots.txt


Other Websites

of top websites are currently blocking W3C_Validator in some way
Updated today