Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.
HTML issues tagged as isolang.
Instead of using the isolang attribute to define the language of the document, you can use lang with an ISO 639-1 two character code.
For example, for Portuguese:
50,000 Accessibility and HTML checks per month. Fully automated.
Let our automated scanner check your large sites using Axe Core and W3C Validator.