HTML Checking for Large Sites

Rocket Validator automatically scans your sites for accessibility issues using the W3C Validator, hosted on our own servers and integrated into our web crawler.

25,000 HTML checks per month. Is that enough for your site?

Save time using our automated web checker. Let our crawler check your web pages on the W3C Validator.

Start tag seen without seeing a doctype first. Expected “<!DOCTYPE html>”.

HTML documents are expected to start with a first line containing the Document Type Declaration, that defines the HTML version used. Since HTML5, it’s just <!DOCTYPE html>, which must appear before the start <html> tag.

Here’s an example of a minimal HTML5 document:

<!DOCTYPE html>

Related W3C validator issues

When was the last time you validated your whole site?

Keep your sites healthy checking for A11Y/HTML issues on an automated schedule.