Decode / Encode
https://toolbox.googleapps.com/apps/encode_decode
Website Ranking Checker
https://www.1and1.com/improve-website-ranking-result
Broken Link Checker
https://validator.w3.org/checklink
You can search to see whether a website is currently dangerous to visit.
Google’s Safe Browsing Technology
Website Speed Checker
https://tools.pingdom.com/
Web Hosting Service Rank
http://www.webhostchecker.com/#full_page_load/USA/USA/Linux/last_month