Known Google filters and penalties

You probably have a Google penalty when your site (or an important page) suddenly disappeared from the index. You will recognize this by lower traffic and lower sales.
But if your site had a steady ranking (for a longtime) for a specific keyword phrase and suddenly the usual ranking drops ten or twenty pages, then this also sounds like a penalty.

But to be certain about this, first do some other ranking checks and visit the most important Webmaster forums and blogs, read some daily SEO feeds to see if this signal has happened to others too. Sometimes during a Google Dance (the moment Google is reindexing his servers), a large rise and fall in rankings can follow for a few days.
A new algorithm implementation can also have this effect.

But if there is no explicable reason for a large drop down (or a removal from the index) of your ranking, then you should think about a possible penalty.

The first thing you should NOT do is contacting Google immediately.

If you have a Google Webmaster account then they probably will contact you with a message if your site has been manual excluded from the index.

 Why does Google remove sites from the Google index?



If not banned from the index, start looking for perceived penalties


Host Server is/was down or having problems during crawl, so pages are not indexed


Robots.txt is blocking the spiders from indexing your site


Problems with crawlers


Domain name problems (DNS, CNAME, problems?)


Lost links causes ranking to drop


Rankings drop because other sites are better or have more links


Rankings drop because of a search engine algorithm shift


Research your logs (site analytics) to find out if there is any unusual activity from a certain moment. If so, try to find out which changes you did before these significant changes.
Contact your host to find out if they are aware of any problems.
Check your competitor's ranking to see if they have changed too.


If you still didn't found any reason, then start to find actual (manual) penalties.

First check Google's Webmaster Guidelines to see if any unethical practice is related to your site.

Read my Bad SEO Practice chapter and try to find out if you (or your Webmaster, or your SEO firm) have recently used one of the black hat techniques in this list.

Google doesn't publicly acknowledge the existence of actual penalties (unless the reason was obvious or part of their guidelines), but we all know they exists. Therefore it is impossible to offer a hard-and-fast rule that can help you look for penalties.


Known (but not officially confirmed) Google penalties/filters:


Google #6 (also called: -5) ranking penalty/filter

In December 2007 some Webmasters noticed that some of their long-term #1 and #2 ranking pages now rank at #6. Many other people experienced the same thing at the same time. Like many of the so called 'numbered' Google penalties (-30, -950), there is no science that can tell us what the exact reason was for this filter.

Aaron Wall (SEObook) has a great article about this filter, so if your site was hit by this filter I recommend you to read this.


Google's -30 penalty

The -30 penalty is a penalty given to websites that use unethical SEO techniques. It started somewhere in 2006. If Google applies this filter, the rankings of that website are downgraded by 30 positions.

Possible reasons for -30 penalty are:


Guestbook spamming


Javascript redirects


Doorway pages


Any other unethical practice published on my Bad SEO Practice list.

People say that this penalty is time related, because it is only for little misdoings. The penalty can be active for about 30 days.


Google's -950 penalty/filter

This a penalty where a website suddenly drops to the end of the result pages. A loss of roughly 950 places.

This penalty is never confirmed by Google itself. The reason of this penalty is again guessing. When this penalty was discovered, some people were trying to get answers for this, including asking Matt Cutts (Google's SE Quality Manager) about this. You never get a straight answer, but one can say that this penalty has everything to do with "over-optimizing" a website. And over-optimizing your website has almost a direct relation with unethical SEO practice mentioned in my SEO don'ts list.


Other known penalty filters


Duplicated content filter


Bad linking filter (linking to bad neighborhood)


Cross-linking penalty (site A-->B-->C-->A)


Excessive use of same (inbound) anchor text


Excessive use of reciprocal linking


Thin affiliate site (many links to affiliates, hardly added value content)


Keyword stuffing


Over optimization penalty


Hidden text or links penalty


Automated page redirects (meta refresh with 0 seconds)


Link buying or selling penalty


Still no problems found in your website?

If you have done all possible checks you could do and still didn't find any possible reason for your unusual drop of ranking, you could try to contact Google and report this as a possible problem.

But one more thing to find out if your site is 'filtered', check


You did find a problem in your website?

Once you've identified and fixed the problem, you should write to Google and ask them to help you fix the problem. This is mostly done by a reconsideration of your site. How do I request reconsideration of my site?



If you practice SEO the way search engines want you to do (by following their quality guidelines), then you don't have to be afraid to get penalized by automatic filters or manual penalties. I know, some people don't agree with these strict rules, but unfortunately we don't have any choice. I also like to speed on the highway when no other traffic is there, but still can lose my license for that.

Keep the guidelines (Google, Yahoo, MSN) and my list Wrong Web design and Bad SEO Practice always in your mind when developing or updating your websites. Build your website for the human being, not for some artificial undefeatable algorithm monster. This can only lead to nightmares.