table { margin: 10px auto 0px auto; width: 95%; } th, td { font-size: 12px; border: 1px solid; padding: 0.5em; text-align: center; width: 125px; } th, tr:first-child { font-weight: bold; width: 150px; } .yes { background: #4F4; } .no { background: #F44; } .doubt { background: orange; } .none { background: #ddd; }
The meta tags for robots you can have on your pages
have been around for quite a while. Search engines have slowly been
adding features to it. This page lists an overview of all the different
values you can have in your tag. First, the official syntax:
[code language="html"]
[/code]
The different robots meta tag values
An explanation of all the different values you can use in the robots meta tags:
indexAllow search engines robots to index the page, you don't have to add this to your pages, as it's the default. noindexDisallow search engines from showing this page in their results. noneThis is a shortcut for noindex,nofollow, or basically saying to search engines: don't do anything with this page
at all.
followTells the search engines robots to follow the links on the page, whether it can index it or not. nofollowTells the search engines robots to
not follow
any links on the page
at all.
noarchivePrevents the search engines from showing a cached copy of this page.nocacheSame as noarchive, but only used by MSN/Live.nosnippetPrevents the search engines from showing a snippet of this page in the search results
and prevents them from caching the page.
noodpBlocks search engines from using the description for this page in
DMOZ (aka ODP) as the snippet for your page in the search results. noydirBlocks Yahoo! from using the description for this page in the
Yahoo! directory
as the snippet for your page in the search results. No other search
engines use the Yahoo! directory for this purpose, so they don't
support the tag.
The resources from the search engines
The search engines themselves have pages about this subject as well:
And of course there's always the official robots.txt pages and Danny Sullivan's big robots meta write up.
Which search engine supports which robots meta tag values?
This table shows which search engines supports which values:
| Robots value |
Google |
Yahoo! |
MSN / Live |
Ask |
| index |
Yes |
Yes |
Yes |
Yes |
| noindex |
Yes |
Yes |
Yes |
Yes |
| none |
Yes |
Doubt |
Doubt |
Yes |
| follow |
Yes |
Doubt |
Doubt |
Yes |
| nofollow |
Yes |
Yes |
Yes |
Yes |
| noarchive |
Yes |
Yes |
Yes |
Yes |
| nosnippet |
Yes |
No |
No |
No |
| noodp |
Yes |
Yes |
Yes |
No |
| noydir |
No use |
Yes |
No use |
No use |
You can block all robots at once by the markup above, or just block one robot by specifying it specifically:
GoogleGOOGLEBOTYahoo!SLURPMSN / LiveMSNBOTAskTEOMA