Some websites like checkpagerank.com displays page rank in one second.I want to know is there any Page Rank API available to check PR so fast?
Do you want to host a PR checker on your own site? If so you would need to use the google API. If you just want to check the PR of the pages on your site you can use the keyword tracker www.digitalpoint.com/tools/keywords
Yes actually i want to put small search like box my visitors to check PR of websites? Which API i have to use?
The Google API doesn't provide a PR function. Some folks have cracked the checksum code needed to query it like the toolbar does. Try googling 'google pagerank checksum' and you should find the info you need.
Yes, they use a formula based on the url of the page you are visiting to produce a "checksum" or code. It is not uncommon to see servers that make repeated/automated requests for PageRank to get "banned" from checking pagerank, and then they have to move to a different server.
Would you like to simplify you comments.What is that "checksum" code. But i have checked various websites who gave PR.And they gave same PR for same particular website. So there must be some common formula or something like that.
Yes, the common formula is the checksum. It's sort of like a secret code. You input a url, and after running through the "formula" you have a long string of numbers and letters. You need this string in order to request the pagerank.