After thinking for numerous hours, I'm starting to think that google discovered duplicate content in a unique way.

I have a website that presents photos. I have a desktop version and a mobile version. The differences between the two is that the mobile version is a slimmed down version with fewer features.

This is where I think the problem begins.

On the desktop site, some features have many options, where as on the mobile site, there is only one option. I configure my site so that mobile user who attempts to use an invalid option will be redirected to the correct option.

For example, on a specific gallery of my desktop site, users can choose to view 100, 200, or 500 picture thumbnails per page. In this case, example URLs that could be accessed are:


On the mobile site, users can only view 100 picture thumbnails per page. Example URL is:


What I believe google does is attempt to access every desktop link on a mobile device just to see what happens.

I currently have it set so that any desktop URL accessed by a mobile device is redirected to the same URL. The resulting mapping is then as follows:

http://example.com/100-per-page = http://m.example.com/100-per-page
http://example.com/200-per-page = http://m.example.com/100-per-page
http://example.com/500-per-page = http://m.example.com/100-per-page

For every redirect, I issue an HTTP 301 status code. I begin to think that google will think these three URLs are duplicate to each other when accessed from a mobile device:


I did however receive a faulty redirect error on one link when I configured it this way and reading elsewhere makes me thing this error means duplicate content.

I have an idea that I think is ridiculous to implement but I feel its the only way to prevent duplicate content. I feel I need to almost make doorway pages for each URL that isn't available on the mobile site with a message explaining why and what users can do and with using an HTTP 200 status. For example, I feel I could make a page with a text like:

"This feature is only available on desktop computers. On mobile, only 100 thumbnails per page are available. Click the button below to view them"

Is this the way to go or is there a better way to eliminate faulty redirects and duplicate content?

  • This is what the canonical tag is for.
    – closetnoc
    Commented Jul 3, 2015 at 3:48
  • but using that wouldn't redirect mobile users to the mobile site tho. Commented Jul 3, 2015 at 4:14
  • You would still redirect, just use a canonical tag on your mobile pages so that 100-per-page, 200-per-page and 500-per-page point to 100-per-page- or as it would be in reality 100-per-page referring to itself but it looks like these pages point to 100-per-page.
    – closetnoc
    Commented Jul 3, 2015 at 4:31
  • In fact, you should be using a canonical tag on your mobile pages to point to your non-mobile pages and vice versa anyway. This would solve the problem.
    – closetnoc
    Commented Jul 3, 2015 at 4:45
  • I do have that and it works fine if a desktop system accesses the site. I'm looking at when the mobile accesses the desktop page. Commented Jul 3, 2015 at 5:25

3 Answers 3


You're doing things exactly correct. Use 301 and there will be no problems.

This is NOT a situation to be using rel=canonical. Canonical linking is for multiple URLs with the same content. This isn't what you have, instead you're trying to move users in the proper direction.

The best case scenario is to just not show the links to the 200 and 500 pages on the mobile site. If you're already doing this, Google isn't crawling desktop links via a mobile spider.

Either way, there's no reason to worry.


  • Thanks. and after further research, my problem is rather worse and I made a thread on it here. Commented Jul 3, 2015 at 16:53

You say you are getting a message about faulty redirect, so not why you think that means duplicate content?

Google are pretty clear about redirecting smart phone users if there isn't a matching page

Faulty redirects

A faulty redirect occurs when a desktop page incorrectly redirects smartphone users to a smartphone page not relevant to their query.

If a page on your site doesn’t have a smartphone equivalent, keep users on the desktop page, rather than redirecting them to the smartphone site’s homepage. Doing nothing is better than doing something wrong in this case.

So Google are simply detecting that you are redirecting them to a different page on the mobile version, than on the desktop page.

Although yes it could be argued its the best matching page to send them too, but technically it is not, so you are getting this warning message.


So you're telling us the page does not exist (for mobile users)? That means it should be a 404 redirect. The 301 means that the page has moved, but it simply doesn't exist.

  • It does exist but in a different format than what the desktop version has. Commented Jul 6, 2015 at 17:38

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