I believe my web site has been banned from Google

No web site is banned without a reason. The practice is mostly used for domains which have been in violation of the Terms and Conditions of the Google Search Engine, and/or were breaching policies of Google Inc. Bans may come without a warning, and are most of the time based on automatic alerts by quality filters, followed by human evaluation. If the web site is found to be unacceptable to be shown for users as a result, it is then unacceptable for the Google index. It then may be removed from the result pages, and blacklisted in the database. The IP address, and link network the domain had connections with may also be affected. Repeated abuse from different domains, but same IP address / range / network may result in the ban of all affiliated domains and web sites, especially if these are all owned by the same entity.

+ Symptoms: Web site does not appear in the Google index at all. No search query will bring up any information on its pages, not even one for its own domain name. An almost sure indication of a ban is when the site:(example.com) command shows zero results in Google search. You may also use the info: command in the same manner. In certain cases banned web sites will show a single, URL-only result for these two queries for a short period, before being excluded completely.

+ Common reasons: Illegal or highly questionable content or practices. Major accessibility and usability issues arising from under- or over-optimization. Spam. Linking to either of the above. Being hosted, linking to or being cross referenced in a network of web sites practicing either of the above.

+ Resolution: Examine your web site based on the Google Webmaster Guidelines and for possible breaches of Google policies, correct the problems and do a reinclusion request. Make sure you don't send a request for pages that still need additional work to comply with the Terms and Conditions of Google. Once the web site has been re-evaluated, it may be accepted back into the Google index, provided it has addressed all problems. Reading through the articles on this web site, and following up on the resources presented, may provide you with hints on what to look for when diagnosing your pages. However most of the time, owners of banned web sites know all too well what they were banned for. For the rare exception, your web site may not have any other problems than unintentionally showing false indications of being spam or other unacceptable content, is being seen as affiliated with another banned domain, or is seen within a network of such web sites.

For more information on possible causes and their resolution read up on TrustRank, Buying links, Link Schemes, Bad neighborhood, Accessibility and Usability issues, Scraper sites, and Reinclusion requests.

You may also open the + Website Diagnostics Panel to help you diagnose your web site.