What if page exists for desktop but not mobile?

[friendoffood]

I have a domain (no subdomains) that serves up different dynamic content for mobile/desktop pages--each having the exact same page url, kind of a semi responsive design, and will be using "Vary: User-Agent" to give Google a heads up on this setup.

However, some of the pages are only valid for mobile or only valid for desktop.  In the case of when a page is valid only for mobile (call it mysite.com/mobile-page-only ), Google Webmaster Tools is giving me a soft 404 error under Desktop, saying that the page does not exist, Apparently it is doing that because my program is actually redirecting the user/crawler to the home page.  It appears from the info about soft 404 errors that Google is saying since it "doesn't exist" I should give the user a 404 page--which I can make it customized and give the user an option to go to the home page, or choose links from a menu, etc..

My concern is that if I tell the desktop bot that mysite.com/mobile-page-only basically is a 404 error (ie doesn't exist), that it could mess up the mobile bot indexing for that page--since it definitely DOES exist for mobile users..

Does anyone here know for sure that Google will index a page for mobile that is a 404 not found for desktop and vice versa?  Obviously it is important to not remove something from an index in which it belongs, so whether Google is careful to differential the two is a very important issue.  Has anybody here dealt with this or seen anything from Google that addresses it?  Might one be better off leaving it as a soft 404 error?

EDIT: also, what about Bing and Yahoo?  Can we assume they will handle it the same way?

EDIT: closely related question--in a case like mine does Google need a separate sitemap for the valid mobile pages and valid desktop pages even though most links will be in both?  I can't tell from reading several q&a on this.

Thanks, Ted

[friendoffood]

Monica,

I'm going to open a new thread to ask a similar question, as I think I didn't ask it very well.

Thanks for your input,

Ted

[friendoffood]

Thanks.  If I understand you, the mobile bot won't crawl a url that the desktop bot has said needs to be fixed for it to work right for desktop. . Would you agree that doesn't really sound right on Google's part, since the url is fine for mobile use?  I don't know why it wouldn't crawl for mobile, but if that's the way it is I can try fixing it on desktop to see if that enables the mobile to get crawled.

Once I do that I guess I'll find out whether a 404 not found for desktop will disable it from crawling for mobile (yes that link is accessible from other pages)--I was hoping to avoid trial and error on that because the time lag seems like it would be hard to pin down.

In a nutshell here's what I'm concerned will happen:

Google mobile bot crawls my mobile page and indexes it:  Then the desktop bot crawls the same url and gets a 404 not found.  Because of the desktop not found, Google removes it from the mobile page index.

I don't see a good way to test that since it depends on when each crawler is crawling.  And, if this is what it is doing, I can't think of a good solution to having a responsive site with some content meant only for mobile indexing or only for desktop indexing.

[MonicaOConnor]

If a URL is labeled a 404 it will not be crawled again unless there is a reason to, you mark it as fixed, or you edit the link in some form or fashion. Mark it as fixed and see if the error comes back. There is no harm in doing this.

Can you get to the page on your mobile device just by clicking through your site? If you can, that is good, it will eventually encourage a mobile bot to crawl it. If you can fetch and render as google, then I would just give it some time. I am not sure if there is a string of code you can add to the head of that page telling the robots that it is a mobile only page. I don't know how that works.

I would just mark it as fixed right now and see what happens over the next couple of days.

[friendoffood]

Hi Monica-thanks for your reply:

Ok, for a page that is supposed to be mobile only within a responsive-like setup(ie one domain) here's what I see:

The desktop bot crawls the link and gives a soft 404 error -- presumably because the page is currently being redirected to the home page.

The mobile bot is not crawling that link despite it being prominent on the main site home page, as my dbase is tracking the bot crawling and is not showing that it crawled that link for mobile (but is for desktop), and a search on my smartphone doesn't show that link either (even though it does show other links for pages used by both)..  **Yet, if I fetch the mobile only page in webmaster tools using their mobile bot it finds it and renders it perfectly. ** So, why isn't it crawling it?  Is it because when the mobile bot crawls it first looks and sees that that link is already 'flagged'  as a soft 404 for the desktop?  Or, is it because the mobile crawler is getting hung up on a link on the home page for mobile that has nothing to do with this mobile-only link?

It appears that the mobile bot is influenced by the desktop bot results--which is my fear:  It seems to me their 2 bots should be independent of each other.  If they aren't independent then if I change it to a 404 not found for desktop, would that even help, or would that prevent the mobile bot from ever trying to crawl it?

I would think that anybody who has a responsive page design and has blocked out certain content so that it renders only for mobile or only for non-mobile has had to face this issue.

Not sure what to do--I could fix the soft errors--change them to 404 not found and just see then if Google starts indexing for mobile or not, but was hoping to get some feedback before experimenting.

Thanks again, and please share more if you have more thoughts!

[MonicaOConnor]

Did you look at your Mobile 404 errors? Google uses a different bot for mobile sites and anything related to that mobile page. Chances are, if it isn't reflecting a 404 in the Mobile errors in GWT, it is being indexed properly.

Check it out from you phone. Google the exact keyword and your company name. See if you can get to the page and if it is in fact the correct page.