Minify your HTML by removing all the unnecessary characters.
Minify your JS by removing all the unnecessary characters.
Get all possible details about a domain name.
Use the Google translator API to generate text to speech audio.
Take an IP and try to look for the domain/host associated with it.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Extract email addresses from any kind of text content.
Get the web-host of a given website.