How to safely exclude search result pages from Google's index?

[llamb]

Hello everyone,
I'm wondering what's the best way to prevent/block search result pages from being indexed by Google. The way search works on my site is that search form generates URLs like:
/index.php?blah-blah-search-results-blah

I wanted to block everything of that sort, but how do I do it without blocking /index.php ?

Thanks in advance and have a great day everyone!

[JaneCopland]

Hi Louise,

If you can ID the parameters, you can also look at blocking these in Webmaster Tools. This page explains more. As with any blocking of URLs, of course, proceed with caution.

[evan89]

I agree that  can be effective. The reason I suggested the robots.txt is because Louise mentioned "blocking and preventing" as an objective. Robots.txt are particularly useful in the example where results from a search bar or something of that nature is involved. A NOINDEX, FOLLOW will not prevent bots from getting tired and dizzy, whereas the robots.txt can "block and prevent" bots from crawling certain parameters.

With all of that said, I think it is important to understand whether you need the bots to crawl and not index (in which case Spencer's answer is correct), or if you need to prevent bots from crawling the parameters altogether.

Hope that is more clear

[spencerhjustice]

I'm not sure that robots.txt is effective when url parameters are involved.

I would just add a meta robots tag to the head section of the search results template:

[evan89]

If you are able to identify a url parameter, you may excluded them using robots.txt. Here is a great resource on Robots.txt - http://a-moz.groupbuyseo.org/learn/seo/robotstxt