Does Google use ETags?

...with If-None-Match validation?

[espeed]

In the thread entitled Are you using If Modified Since? [webmasterworld.com], someone asked, "Does Google use ETags
(with If-None-Match validation)?".

Apparently, googlebot does not send the ETag and If-None-Match
headers. Here's an example of what googlebot is sending:

If-Modified-Since = Thu, 21 Aug 2003 04:37:51 GMT 
User-Agent = Googlebot/2.1 (+http://www.googlebot.com/bot.html) 
From = googlebot(at)googlebot.com 
Accept = text/html,text/plain,application/* 
Host = example.com 

[plasma]

It doesnt even handle if-modified-since so that it could be of use.
The googlebots all seem to have their own index and don't synchronize themselves.
That way the bots come back 50days after the files modified.

With dynamic pages, changing very often, this isn't much of a help.
However, thanks to googles guidelines we implemented it and it's really useful and speeds things up a lot.

I too prefer ETags as they are more accurate (strong validator) and even easier to implement.

I hope they'll support it in future.