I have a product page with options in select list (ex : color of the product etc...). You accede to my product with different urls :
If you accede with the url www.mysite.com/product_1.html#/color-green, the option green of the select list is automatically selected (with javascript).
If i link my product page with those urls, is there a risk of duplicate content ? Is it good for my seo ? thx
At one time I saw Google indexing the odd #ed URL and showing them in results, but it didn't last long. I think it also required that there was an on page link to the anchor.
Google does support the concept of the hashbang (#!) as a specific way to do indexable anchors and support AJAX, which implies an anchor without the bang (!) will no longer be considered for indexing.
Either way, Google is not stupid. The the basic use of the anchor is to move to a place on a page, i.e. it is the same page (duplicate content) but a different spot. So Google will expect a #ed URL to contain the same content. Why would they punish you for doing what the # is for?
And what is "the risk of duplicate content". Generally, the only onsite risk from duplicate content is Google may waste it's time crawling duplicate pages instead of focusing on other valuable pages. As Google will assume # is the same page it is more likely to not event try the #ed URL.
If you're worried, implement the canonical tag, but do it right. I've seen more issues from implementing it badly than the supposed issues they are there to solve.
You need to use canonical urls in order to let the search engines know that you are aware that the content seems duplicated.
Basically using a canonical url on your page www.mysite.com/product_1.html#/color-green to go to www.mysite.com/product_1.html tells the search engine that whenever they see www.mysite.com/product_1.html#/color-green they should not scan this page but rather scan the page www.mysite.com/product_1.html
This is the suggested method to overcome duplicate content of this type.
See these pages:
SEO advice: url canonicalization
A rel=canonical corner case
Both answers above are correct. Google has said they ignore hashtags unless you use hash-bang format (#!) -- and that really only addresses a certain use case, so don't add it just because you think it will help.
Using the canonical link tag is the right thing to do.
One additional point about dupe content: it's less about the risk than about a missed opportunity. In cases where there are dupes, Google chooses one. If 10 sites link to your site using www.example.com and 10 more link using just example.com you'll get the :link goodness" benefit of only 10 links. The complete solution to this involves ensuring that when users and Google arrive at the "wrong" on, the server responds with an HTTP 301 status and redirects the user to the "right" one. This is known as domain canonicalization and is a good thing for many, many reasons. Use this in addition to the "canonical" link tag and other techniques.
