Javascript and the Major Search Engines

[rfontaine]

Do Google, Yahoo, MSN, and Ask read javascript on a website?

If I were to include a javascipt enabled test on a web page and google visited the page what would the result be?

What about a typical "bad bot"?

The reason I am asking is I am seeking a way to stop the bad bots from scraping a website. Not considering the fact that some legit visitors have javascript turned off, would doing a javascript enabled test, and then sending those who have javascript disabled different content, discourage some of the bad bots but not turn away the major good spiders?

[Bernard Marx]

Search engines don't activate Javascript (as yet). Any content that is created by Javascript simply won't be seen.

Excluding "bad bots" is an issue, but not for client-side Javascript. The forum you should turn to for advice depends upon your server ¦ server scripting language.

[rfontaine]

Well, when I look at Google's cache of a page I often see content that has been generated by javascript. I take this to mean Google is actually able to read javascript.

[Bernard Marx]

Are you sure? I see result summaries with this sentence all over the place:

"Please enable Javascript to view this page"

...or variations thereof

The cached content is a different issue. Your browser is executing the Javascript when it reads the page. It doesn't mean that Google was aware of that content that the script creates - It just cached the page, as-is.