1. digpagerank.com to check for valid domain PageRank
2. diagnosticoweb.com to check for valid domain PageRank
3. checkpagerank.net or http://www.whatsmypagerank.com/ to check valid PageRank and knowing the number of back links, dmoz, and domain age
4. Google.com input keyword:
- Info: namedomain.com for checking domain information is valid and whether there is in google
- Site: namedomain.com to check whether the domain indexed in google
- cache: namedomain.com to check whether the domain tercache on google
note: replace namedomain.com match the address (url) you want to check domain