Doctype checker

Detects outdated HTML tags that should be replaced with modern alternatives.

Get the HTML language attribute from a webpage.

Check if a webpage declares its character encoding.

Check if a website has HTTP Strict Transport Security (HSTS) enabled.

Enter your website URL and you will get an instant preview of how it would look when finding it on Google.

Get all possible details about an SSL certificate.

Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.