So you’ve built a site and started to see some Google traffic and feel happy. But one day you are trying to figure out why your site is no longer coming up in the search engines, or if you have noticed a decrease in traffic, the website might have been penalized for one reason or another. Google Penalty is the biggest nightmare for every website owner. It may affect your site ranking and it results in poor traffic and less visitors. As a result, your site popularity will decrease.

Here are the few steps which will help you to determine Google penalty on your website-

1. Check your Google Webmaster Tools account for alerts or site crawl errors;
2. Perform [site:yoursite.com] search in Google to see if Google reports same number of indexed URLs;
3. Search for the Entire Address  ”http://yourdomain.com” in Google .This time, do a search for the full address, including the protocol. For example, http://example.com. If the site shows up in the results, it is fine. If you get no results, or if you only get the main page, Google has probably penalized your site.
4. Take a look if Google toolbar PR has changed (graybar PR might be a signal of penalty);
5. Check your site ranking for a “domain-name” search (without the TLD).
If such a query puts you in the fifties, it’s almost (!) guaranteed to be a penalty.
6. Check if Google has blacklisted your site as unsafe for browsing (type http://www.google.com/safebrowsing/diagnostic?site=mysite.com with your domain at the end).
7. Review your user generated content (for possible links to bad neighborhoods or improper vocabulary);
8. Check your server for any malware attack, Malware is the reason of Google Penalty too.
9. Copy a long phrase from your page and search Google for the exact match – make sure this very page (not the home page, not other sites scraping yours) is ranked #1;
10. Check if your URL can only be seen by adding &filter=0 to the search URL – or clicking on the “show omitted results” link (this means you were hit by the duplicate content penalty);

Any other? Please share your way to diagnose a penalty.