Wednesday, February 25, 2009 at 6:50 AM
A little while ago, Google and other search engines announced support for a canonical link element that can help site owners with duplicate content issues. I recreated my presentation from SMX West and you can watch it below:
You can access the slides directly or follow along here:
You can access the slides directly or follow along here:
By the way, Ask just announced that they will support the canonical link element. Read all about it in the Ask.com blog entry.
Thanks again to Wysz for turning this into a great video.
Thanks again to Wysz for turning this into a great video.
In fact, you might not have seen it, but we recently created a webmaster videos channel on YouTube. If you're interested, you can watch the new webmaster channel. If you subscribe to that channel, you'll always find out about new webmaster-related videos from Google.
20 comments:
I have a nerdy technical question: why use the "rel" attribute and not the "rev" attribute?
According to the specs, rel is for forward links, rev is for backward links. I would categorise canon links as "backward", because non-canon links are variations of canon; canon links are at the "beginning", if you will.
Just a thought ;)
Thanks for the follow up to the webmaster post. I'm more of a graphical learner, so this video helps.
I guess the laptop brand you're flashing doesn't qualify as product placement since they don't sell it anymore.
Will this be added to Blogger?
Thanks you for all your efforts to help webmasters and your great work with other search engines.
I was born on 12 Feb. 1980 :) Thank's
A couple questions for this example:
example.com/page1?page=3
example.com/page1?sortby_price_asc
example.com/page1?sortby_date_desc
all have cannoical link points to:
example.com/page1
1. Will Google eventually or quickly remove all pages with canonical link element but just keep the page the canonical link points to?
2. Will this hurt the pagerank of example.com/page1 since different variance with different sorting algorithm would have different unique nature such as keyword density. WIll example.com/page1 be able to have all those unique nature or G will just treat it based content on example.com/page1?
I run a price comparison site with 17 million products.
How can I implement this?
very good! coffly.com
I do not believe all this SEO marketing bullshit, it's just a perfect example on how to get money from your client
@Matt Cutts... these elements and attributes are beginning to feel like Search Engines, in particular Google are telling webmasters how to build sites.
Do these tags validate? NAFAICS...
Will they ever validate? W3C chose to use the robots tag to nofollow their sponsorship page. What's that say about what the SEs' are doing?
Do Search engines care? IMO, they should. AIUI, Google is a Member of the W3C, has the Chrome browser, yet... adds elements and attributes to HTML with no RFC, no input from the webmaster community and the tags don't seem to validate so they are saying "Heay break your code there boys, it's no big deal we're more important then protocals! Sorry, I actually experienced the browser wars... nobody benefitted from that except Microsft who were pretty much sittin' with the desktop where Google is now with search. I had to jump through hoops for hours to get things to work in both... I'm starting to feel like that is about to start again
Not that I really care about validation, but others do. What about them?
@Matt, all the major engines started on the same page with the noFollow for blog Comments... yet ended up divided on paid ie: no support for that use. See whrere I'm going?
Now on this one it's kinda' "trust us we're going to make the implementation up as we go". Oh... and by the way we'll just choose to interpret that implementation how we please"... using the same blackbox that houses QualityScore, NoFollow... with who knows what to come next?
Sorry.... this benefits who? no one but SEs and developers with questionable development practices. This makes link development more complicated and will further confuse many in the community. To those who are goind to jump on the wagon think about it... do you know about every IBL to your site? If you use this tag you better. ;-)
@RichUncleSkeleton - because HTML 5 removes the "rev" attribute - it will no longer exist.
I am a part time web developer and now want to switch myself to Web2.0 Application Development, i was searching some stuff about Web2.0, Social Media, Social networking and Blogs, by passing Google Search i came acroos your website which has excellent resources of Web2.0 and e-Marketing.
Hopefully canonical issues will be spotted through webmaster tools in the future.
If I place a noindex,nofollow AFTER the canonical link (to catch crawlers from search engines not currently handling the canonical link), will the canonical link still function correctly?
Thanks for a video about the issue of canonical site url.
This is good to know all.
Thanks again.
@RichUncleSkeleton and @Ian_M -
More to the point, "rev" attribute would require that the "canonical" (i.e., source) document know about all derivatives produced from it -- and more troublesome, enable a malicious user to cause many documents which were *not* derivative to be treated so, by modifying (or creating!) an entirely un"rel"ated page and asserting that *this* page is canonical for all of *those*.
Sometimes it's better to look at the full definition of an element or attribute, than at the shorthand.
rel This attribute describes the relationship from the current document to the anchor specified by the href attribute. The value of this attribute is a space-separated list of link types.
rev This attribute is used to describe a reverse link from the anchor specified by the href attribute to the current document. The value of this attribute is a space-separated list of link types.
What's canonical?
Thanks for such informative video.I want to now how canonical links are beneficial for SEO.
I have lot of pages in my application like my.jsp, my1.jsp, my2.jsp so on....... so i need to put this rel="canonical" in all pages are only one page??
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