Solve duplicate content issues by using robots.txt

[JohnHuynh]

Hi,

I have a primary website and beside that I also have some secondary websites with have same contents with primary website. This lead to duplicate content errors. Because of having many URL duplicate contents, so I want to use the robots.txt file to prevent google index the secondary websites to fix the duplicate content issue. Is it ok?

Thank for any help!

[JohnHuynh]

yes, robots.txt is the bad way, I will try to use canonical tag. Thanks for your help!

[simon_realbuzz]

Using robots.txt is perhaps not the best way of doing it. Using the canonical or a noindex meta tag would likely be best. I think the reasons for this are best summed up in this article which explains, probably better than I could, why robots.txt is not the best way of dealing with duplicate content. Hope this helps.

[JohnHuynh]

I have tried to use cross-domain canonical, but this is too difficult for me. So, I want to confirm if I use the robots.txt file is ok or not?

Thanks

[simon_realbuzz]

Why not use a cross-domain canonical whereby you reference the pages on your primary website as the canonical version on your secondary websites, thereby eliminating the duplication.

For example on each page that is duplicate on your secondary website you would add the following to the head to reference the primary pages: