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.

Important pages of my web site are shown as supplemental results

Supplemental Results are not necessarily an indication of a quality filter flag. Pages that are perceived by the web site owner to be important, yet showing the Supplemental tag on their results may or may not be caused by factors that could be seen as a problem that needs to be or could be corrected. The supplemental index is seen as a secondary database of results for unique information appearing on, and sometimes only on less important pages, URLs that are unlikely to be looked or shown for generic search terms, but will remain in the index for more refined, obscure queries.

+ Symptoms: Pages of the web site that previously were shown as normal results are now Supplemental Results, thus rank significantly lower than other pages and web sites.

+ Common reasons: Inconsistent, linear, or otherwise corrupted navigation. Accessibility issues resulting in PageRank not flowing through the web site in a way its owners would like it to. Low PageRank of the pages on the web site. Duplicate content. Also, URLs that have been changed, redirected or deleted may be featured with their old versions in the supplemental index along with a cached snapshot of their last seen state up to a year. In these cases make sure to check whether the URL in question also shows as a normal result, which would be the updated version of the same page.

+ Resolution: Examine your web site structure thoroughly for duplicate content, navigational inconsistencies and link hierarchy. Also, as the web site is seen more and more important as a resource, gaining more quality inbound links will raise its PageRank and allow its inner-level pages to be viewed as a relevant result for broader queries, and may eventually be transferred to the normal index. Make sure to pass the proper amount of weight to pages to be considered important by using Anchor text links instead of javascript, flash, image links.

See more information and hints on the reworked Supplemental Results index , Duplicate content, proper Website navigation and PageRank in the related articles.

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

http://diagnostics.googlerankings.com/supplemental.html

I believe my web site has been penalized by Google

A "penalty" is a common phrase referring to cases where an established page, pages or an entire web site/domain is suddenly showing at significantly lower positions on search result pages than used to. Most of the time these symptoms are the result of a quality / relevancy / spam filter flagging a URL or all URLs on a domain. Most of such problems can be tracked down to either minor or major quality problems, the level of relevancy being questioned or the linking profile being seen as unnatural. These URLs are viewed as less likely to be valued by users doing searches on Google, but not excluded from the Index entirely. The vast majority of these issues are an automatic response to what the Google algorithms consider "lower quality results" ( results, and not web sites ) and while penalties are far more uncommon than one might think, they can be viewed as one of the parameters that the ranks consist of. Hence they can be dealt with by addressing the problems, so during subsequent crawls, the freshly calculated parameters may exclude these flags, and allow a higher position on the result pages. Just as in the case of manual bans, no web page / site is penalized without a reason, although in certain cases an automated penalty may arise not from an actual practice, but indications of a practice. There is no board to request a re-evaluation from, as all pages that are being indexed are also being constantly re-evaluated by the algorithms, based on the new data Googlebot gathers from web sites. A corrected accessibility issue, duplicate content or previously unset canonical URL etc., will be thus picked up automatically, and the pages will gradually rank better. In rare cases where a penalty is not lifted automatically even after the previously filtered pages/references have been crawled and indexed by Google, filing a reinclusion request may be needed. However, allow at least an entire cycle of Googlebot crawling these resources before deciding to come to this conclusion. Should a web site be penalized because of off-site reasons, check whether these URLs have been crawled since the correction or not.

+ Symptoms: Web page / site is in the Google index, but ranks significantly lower than before, sometimes in a noticeable pattern of losing its position throughout queries for important keywords and keyphrases or URL patterns, subdomains. In some cases web site is not the first result for a search of its own domain name. Indications such as a drop of PageRank to zero, without the page being excluded from the index, may also provide information on where the problem lies.

+ Common reasons: Massive overuse or misuse of elements on a web site, irregular page or inbound link growth, irregular or off-topic linking patterns, accessibility and usability problems, linking to Bad Neighborhoods, massive duplicate content problems and more.

+ Resolution: Examine your web pages based on the Google Webmaster Guidelines and for possible breaches of Google policies, correct the problems, and allow the changes to take root as consecutive crawls update the data associated to the URLs. There are a wide range of reasons why a web page or web site may be "penalized", but more often than not, just by asking yourself what you ( or sometimes others associated to your site ) might have done to trigger such a reaction, you will probably be right on spot. The Google algorithms are designed to simulate and provide a user experience, a view on quality that is quite easy to comprehend by applying common sense. If it is, or it looks like as if it was the misuse of page elements to artificially gain relevance, if it is, or it looks like as if it was a link scheme to haste the accumulation of PageRank, if it is, or looks as if it was spam, cloaking, plagiarized ( or duplicate ) content, etc., it may sooner or later trigger a flag from a quality filter, or in other words a "penalty". The filters that are applied to the vast amount of data collected by Googlebot are constantly updated based on researches on both user and web site behavior, examining "natural" and "artificial" linking patterns, adjusting accessibility standards, and taking many other factors into consideration as well. Should a penalty not be lifted even after all previously filtered on and off-site problems have been corrected, you may need to file a reinclusion request as well. Allow at least an entire cycle of Googlebot crawling these pages before coming to this conclusion.

To identify the kind of quality issues your web page/site faces, follow the information and resources provided in the articles to give you some general hints on what to correct. Keep in mind that first you have to look for the obvious reasons, and only after being able to exclude them should you turn to the less common, more complex possibilities. In this process, you'll need to learn how to look at your own web site as a critic, an average user, and even as a competitor.

For well established web sites that had ranked reasonably good for up until recently, the idea of triggering relatively new search quality filters may be the first thing to check the pages against. See more information under Duplicate content, Supplemental Results, Canonical URLs, Bulk update, The "sandbox", Omitted results and TrustRank.

Web sites that have had a long time case of ranking lower than their on-page relevance and linking profile alone could indicate, PageRank, TrustRank, Anchor text link, Usability and Accessibility issues, and linking related articles may provide some hints.

If you can exlude with confidence ( or have already fixed ) all on-page and known linking pattern problems, and the penalty still persists, you may need to look for the most rare although at the same time most extreme causes as well, such as Hijacking. Another hint may be that it's not always the doing of the current webmaster or even the content, linking pattern of the actual web site, but the remains of a Historic Domain Penalty. Make sure you know of the history of the domain the web site is hosted on. If the domain name was pre-owned, and it was the previous web site that has been penalized, you may need to bring the change of ownership to the attentnion of Google Inc. to lift the penalty.

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