Why google indexed pages are decreasing?

[SierraPCB]

Hi,

my website had around 400 pages indexed  but from February, i noticed a huge decrease in indexed numbers and it is continually decreasing. can anyone help me to find out the reason. where i can get solution for that?  will it effect my web page ranking ?

[Davinia22]

Hi -

A good question to ask is do you have 400 pages that are relevant, up-to-date and useful to visitors. If you have duplicate content, empty pages and so on a decrease in indexed pages is not necessarily a bad thing. You don't want your SEO efforts diluted across multiple pages when there is only one best page and you don't want your visitors to go to a bad/old page because this would be a poor user experience for them.

My first check would be to look at your XML sitemap. If you don't have one start there (be sure to upload to Google Webmaster Tools). If you do have one check there are no issues (in Google Webmaster Tools) and also have a manual check to ensure that it is using correct tags, indexed all of your pages etc.

Also have a look at your robots.txt file - have you made any changes lately? Blocked sections from being accessed?

Content - do you have lots of pages with similar content. If so you should use rel-canonical tags so that search engines know which page should be indexed.

Find the true amount of webpages you have (and want indexed), tidy up the what and how pages get indexed and then use that number as your benchmark for amount of pages indexed.

Hope that helps,Davinia