This post was sparked from an article I read on ActiveRain called: Beware of Duplicate Content Penalties on your Blog by Roberta Murphy
Based on the comments in the article, there seems to be alot of confusion about duplicate content. There is a huge difference between onsite duplicate content vs. offsite duplicate content
Many of the commenters on Active Rain seem to have blurred the lines a little bit and neglected to make the distinction between the two. They are really 2 different issues.
What Roberta was referring to in her blog post is an onsite duplicate content issue. When you create a blog post and add it to multiple categories, you are creating duplicate content on the blog. Allow me to explain…
An Example of Duplicate Content with Multiple Categories:
When you write a blog post and include it in 4 categories, you are in effect creating about 7 pages on your website with the exact same content (article).
- Blog home page
- Individual blog post page
- Archives page
- Category 1
- Category 2
- Category 3
- Category 4
You can see how adding a post to multiple categories creates onsite duplicate content… Ask yourself, would you ever create a website and include the same article on 7 different pages of the site? Probably not. So why would you do it on your blog?
Will Adding a Blog Post to Multiple Categories Create a Duplicate Content Penalty?
This is the biggest question everyone has… The short answer is NO. You will not be penalized by google for having duplicated content on your website.
But… some of the pages with the dup content may be de-valued in the search engine index. Google is not about to rank 7 pages well for the exact same content. Can you imagine what the search results would look like if it did???
The primary reason to avoid multiple categories for one post is to make sure that Google doesn’t de-value any of your pages. That is the real issue.
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- Follow-Up Post on Building Incoming Links to Your Site
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January 17th, 2008 at 7:51 pm
Justin: As usual, an excellent explanation for a seemingly complex subject. Count me as a subscriber!
January 17th, 2008 at 8:24 pm
Great summary of an oft-confused topic Justin.
Why not just set Categories and Archives to not be indexed? See any drawback to that?
January 17th, 2008 at 8:54 pm
Thanks that helped a lot and as I said in Robert’s post, my client from Google had told me this summer when we closed on his house that Google would not penalize for duplicate content on blogs that you personally own and he said up to 3-4.
He said the real thing Google hates is web sites that are all template with no variety in content.
I did a post yesterday on my blog, and it covered 3 categories, Ann Arbor, Events and Saline. All were valid in the post. So today, I have had 4 different Google Alerts is the category thing why?
January 17th, 2008 at 9:19 pm
@Missy - You’re probably getting google alerts because you mentioned all three of those keywords in the post itself.
@Jay - Yes, I suppose you could use robots=noindex on your category pages, but I find that categories are often great landing pages for search engines. But you could use it on archive pages since they are mostly useless in ranking anyway.
January 18th, 2008 at 2:14 am
Finally an explanation that makes sense! I’ve been wondering about this since last April. Thank you for the clarification.
January 18th, 2008 at 4:17 am
Thank you for clarification Justin. I’ve heard this discussed, and even talked with you about it, but I’ve never seen a good explanation published. Thanks for bringing up the issue. I used to think it was better to put a post in more categories. I feel better being sure of what I am doing.
January 18th, 2008 at 2:46 pm
Great explanation. I read Roberta’s post and then went immediately to my blog and edited some of the categories! How to keep up with it all?
January 21st, 2008 at 11:17 pm
I know loads of people that post duplicate content all over the web. Most say that it doesn’t affect their pages…but what will happen the day that alorithm changes? I think Google will hand out Gimp Slaps to these people.
January 23rd, 2008 at 10:27 pm
This topic is always confusing and most of the time misunderstood. You have presented in a clear, understandable fashion. Thanks. I think some people try to talk when they don’t exactly know what they are talking about.
January 27th, 2008 at 4:35 am
The Google duplicate content thing is mostly a myth, but I agree with a potential change in algorithm. You never know when those smart guys at Google will figure a way to potentially penalize sites if it looks like duplicate content is originating from a single source. Keeping your nose as clean as possible is the most prudent course of action.
February 6th, 2008 at 6:53 am
I think Google penalizing duplicate content is a great idea. Otherwise people would just copy and paste content all over creating even more spammy sites.
February 8th, 2008 at 12:23 am
Even if you don’t get penalized by having the content duped on your own site, it seems to me that your PR will become a bit diluted if you have all of that link-rich content appearing in multiple places. I prefer to keeps the robots away from category pages so that I can save that PR for something better.
February 11th, 2008 at 3:52 pm
Very interesting, I never even thought about having my content in more than one category being a big deal at all. Thanks for the info!
February 14th, 2008 at 12:13 am
Great post, I never thought about duplicate content in that manner. Time to add nofollows
February 15th, 2008 at 3:11 am
Justin very concise in your explanation. I read the post you are refering to and noticed people were confused based on the comments as well. In the case of AR what would be considered the blog home page?
February 15th, 2008 at 3:58 am
On AR, a blog home page would be something like this: http://activerain.com/blogs/hismove
And on AR, your tags act similar to the way categories do on a normal blog.
February 18th, 2008 at 11:39 pm
At PubCon this was talked about by some bloggers that make serious money doing so. They made it pretty clear that in the long run you need to figure out how to keep it so there is only one version of the post that Google is seeing. Great post.
February 24th, 2008 at 3:12 am
This explanation on onsite duplicate content has helped much and I look forward to a post on offsite duplicate content if you are doing one.
I have my blog posts and web pages copied verbatim and the copy cats rank their copied pages higher than me. Makes me sick.
March 7th, 2008 at 3:10 am
Thanks for the thorough explanation about duplicate contents on the blog. If duplicate content is not penalized, I think people will just copy and paste articles and publish as their own.
March 7th, 2008 at 4:18 pm
there are a few plugins that you can install in wordpress to stop google indexing catergory and archive pages. this will mean that duplicate content on your blog would be minimised.
i think the best plugin for this is all-in-one-seo-pack
April 13th, 2008 at 4:08 pm
Thanks for the clarification. I would place posts into different relevant categories with the idea that I wanted to make sure people could find. Now I understand that I could actually be doing myself a disservice.
April 19th, 2008 at 3:58 pm
Thank you for explaining this to me. To me this was a very confusing subject. I corrected my blog this morning.
April 23rd, 2008 at 4:43 pm
Thanks for clearing that one up,
It has baffled me for a long time.
I went stupid on some of my posts when I first started, putting them in 6-7 categories. How much damage does it do if I remove categories after time?
Great Post by the way.
October 20th, 2008 at 12:16 am
Hey Justin,
Nice post, I’ve been considering this for some time now. I’m thinking that using subcategories will help me keep things organized but I worry I may run into the same problem as using multiple categories for a single post. That is, wouldn’t a post that’s assigned to a subcategory also appear in the main category archives too? Thus we’re right back where we started. Any thoughts on how to do use subcategories while avoiding the duplicate content issue?
PS. If you could add the option to subscribe (via a plugin) to comments on posts that would be great!
October 20th, 2008 at 12:30 am
Hi Kevin,
No, subcategories won’t fix the problem unfortunately. If you’re talking Wordpress, the subcategories are virtually identical in the eyes of the search engine. I suggest a plugin like All in One SEO that allows you to noindex the categories and archives. That is really the best way around it. Hope that helps…
BTW, just enabled comment subscriptions… can’t believe I missed that before! Sometimes I forget to just logout of wordpress and just navigate my blog the same way a reader would. Sheesh… sorry about that.
October 20th, 2008 at 9:30 pm
Noindexed categories and archives via Robots Meta plugin by Joost de Valk. Thanks for the advice Justin!