Minify your CSS by removing all the unnecessary characters.
Minify your JS by removing all the unnecessary characters.
Get all possible details about a domain name.
Make sure your passwords are good enough.
Get & verify the meta tags of any website.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Get approximate IP details.
Check if the URL is banned and marked as safe/unsafe by Google.