Moz Q&A is closed.
After more than 13 years, and tens of thousands of questions, Moz Q&A closed on 12th December 2024. Whilst we’re not completely removing the content - many posts will still be possible to view - we have locked both new posts and new replies. More details here.
Block in robots.txt instead of using canonical?
-
When I use a canonical tag for pages that are variations of the same page, it basically means that I don't want Google to index this page. But at the same time, spiders will go ahead and crawl the page. Isn't this a waste of my crawl budget? Wouldn't it be better to just disallow the page in robots.txt and let Google focus on crawling the pages that I do want indexed?
In other words, why should I ever use rel=canonical as opposed to simply disallowing in robots.txt?
-
With this info, I would go with Robots.txt because, as you say, it outweighs any potential loss given the use of the pages and the absence of links.
Thanks
-
Thanks Robert.
The pages that I'm talking about disallowing do not have rank or links. They are sub-pages of a profile page. If anything, the main page will be linked to, not the sub-pages.
Maybe I should have explained that I'm talking about a large site - around 400K pages. More than 1,000 new pages are created per week. That's why I am concerned about managing crawl budget. The pages that I'm referring to are not linked to anywhere on the site. Sure, Google can potentially get to them if someone decides to link to them on their own site, but this is unlikely and certainly won't happen on a large scale. So I'm not really concerned about about losing pagerank on the main profile page if I disallow them. To be clear: we have many thousands of pages with content that we want to rank. The pages I'm talking about are not important in those terms.
So it's really a question of balance... if these pages (there are MANY of them) are included in the crawl (and in our sitemap), potentially it's a real waste of crawl budget. Doesn't this outweigh the minuscule, far-fetched potential loss?
I understand that Google designed rel=canonical for this scenario, but that does not mean that it's necessarily the best way to go considering the other options.
-
Thanks Takeshi.
Maybe I should have explained that I'm talking about a large site - around 400K pages. More than 1,000 new pages are created per week. That's why I am concerned about managing crawl budget. The pages that I'm referring to are not linked to anywhere on the site. Sure, Google can potentially get to them if someone decides to link to them on their own site, but this is unlikely (since it's a sub-page of the main profile page, which is where people would naturally link to) and certainly won't happen on a large scale. So I'm not really concerned about about link-juice evaporation. According to AJ Kohn here, it's not enough to see in Webmaster Tools that Google has indexed all pages on our site. There is also the issue of how often pages are being crawled, which is what we are trying to optimize for.
So it's really a question of balance... if these pages (there are MANY of them) are included in the crawl (and in our sitemap), potentially it's a real waste of crawl budget. Doesn't this outweigh the minuscule, far-fetched potential loss?
Would love to hear your thoughts...
-
I would go with the canonicals. If there are any links going to these duplicate pages, that will prevent any "link juice evaporation" from links which Google can see but can't crawl due to robots.txt. Best to let Google just crawl the page and see the canonical so that it understands that it is a duplicate page.
Having canonicals on all your pages is good practice anyway, as it can prevent inadvertent duplicate content from things like query parameters.
Crawl budget can be of some concern if you're talking about a massive number of pages, but start by first taking a look at Google Webmaster Tools and seeing how many of your pages are being crawled vs the total number of pages on your site. As long as this ration isn't small, you should be good. You can also get more crawl budget by building up your domain authority by building links.
-
I don't disagree at all and I think AJ Kohn is a rock star. In SEO, I have learned over time that there are rarely absolutes like always do this or never do that. I based my answer on how you posited the question.
If you read AJ's post you will note that the rel=canonical issue comes up with others commenting and not in the body of his post. Yes, if the page is superfluous like a cart page or a contact page, use the robots.txt to block the crawl. But, if you have a page with rank, links, etc. that help your canonical page, how are you helping yourself by forgoing rel=canon?
I think his bigger point was that you want to be aware and to understand that the # of times you are crawled is at least partially governed by PR which is governed by all those other things we discussed. If you understand that and keep the crawl focused on better pages you help yourself.
Does that clarify a bit?
Best -
Hi, even if you use robots.txt file to block these pages, Google can still pick the references of these pages from third-party websites and can crawl from there. Such pages will not have the description snippet in the search results and instead will show text that reads:
A description of this result is not available because of this site's robots.txt.
So, to fully stop Google from crawling these pages, you can go in for the page-level meta robots tag along with the robots.txt method. The page-level robots meta tag complements robots.txt method.By the way, robots.txt file can definitely save you some crawl budget. I don't think you should be thinking much about crawl budget though, as long as your website is super-easy to crawl with simple text-based internal links and stuff like, super-fast servers etc.,
Those my my two cents my friend.
Best regards,
Devanur Rafi
-
Thanks for the response, Robert.
I have read lots of SEO advice on maximizing your "crawl budget" - making sure your internal link system is built well to send the bots to the right pages. According to my research, since bots only spend a certain amount of time on your site when they are crawling, it is important to do whatever you can to ensure that they don't "waste time" on pages that are not important for SEO. Just as one example, see this post from AJ Kohn.
Do you disagree with this whole approach?
-
Yair
I think that the canonical is the better option. I am unsure as to your use of the term "crawl budget," in that there is no fixed number of times a page or a site will be crawled versus a second similar site for example. I have a huge reference site that is crawled every couple of days and I have small sites of ten pages that are crawled weekly or less. It is dependent on the traffic and behaviors of that traffic (which would include number of inbound links, etc.) and on things like you re-submitting sitemap, etc.
The canonical tag was created to provide the clarification to the search engine as to what you considered to be the relevant page. Go ahead and use it.Best
Robert
Got a burning SEO question?
Subscribe to Moz Pro to gain full access to Q&A, answer questions, and ask your own.
Browse Questions
Explore more categories
-
Moz Tools
Chat with the community about the Moz tools.
-
SEO Tactics
Discuss the SEO process with fellow marketers
-
Community
Discuss industry events, jobs, and news!
-
Digital Marketing
Chat about tactics outside of SEO
-
Research & Trends
Dive into research and trends in the search industry.
-
Support
Connect on product support and feature requests.
Related Questions
-
Robots.txt & Disallow: /*? Question!
Hi, I have a site where they have: Disallow: /*? Problem is we need the following indexed: ?utm_source=google_shopping What would the best solution be? I have read: User-agent: *
Intermediate & Advanced SEO | | vetofunk
Allow: ?utm_source=google_shopping
Disallow: /*? Any ideas?0 -
Rel=canonical and internal links
Hi Mozzers, I was musing about rel=canonical this morning and it occurred to me that I didnt have a good answer to the following question: How does applying a rel=canonical on page A referencing page B as the canonical version affect the treatment of the links on page A? I am thinking of whether those links would get counted twice, or in the case of ver-near-duplicates which may have an extra sentence which includes an extra link, whther that extra link would count towards the internal link graph or not. I suspect that google would basically ignore all the content on page A and only look to page B taking into account only page Bs links. Any thoughts? Thanks!
Intermediate & Advanced SEO | | unirmk0 -
Robots.txt - Do I block Bots from crawling the non-www version if I use www.site.com ?
my site uses is set up at http://www.site.com I have my site redirected from non- www to the www in htacess file. My question is... what should my robots.txt file look like for the non-www site? Do you block robots from crawling the site like this? Or do you leave it blank? User-agent: * Disallow: / Sitemap: http://www.morganlindsayphotography.com/sitemap.xml Sitemap: http://www.morganlindsayphotography.com/video-sitemap.xml
Intermediate & Advanced SEO | | morg454540 -
Baidu Spider appearing on robots.txt
Hi, I'm not too sure what to do about this or what to think of it. This magically appeared in my companies robots.txt file (literally magically appeared/text is below) User-agent: Baiduspider
Intermediate & Advanced SEO | | IceIcebaby
User-agent: Baiduspider-video
User-agent: Baiduspider-image
Disallow: / I know that Baidu is the Google of China, but I'm not sure why this would appear in our robots.txt all of a sudden. Should I be worried about a hack? Also, would I want to disallow Baidu from crawling my companies website? Thanks for your help,
-Reed0 -
Robots.txt, does it need preceding directory structure?
Do you need the entire preceding path in robots.txt for it to match? e.g: I know if i add Disallow: /fish to robots.txt it will block /fish
Intermediate & Advanced SEO | | Milian
/fish.html
/fish/salmon.html
/fishheads
/fishheads/yummy.html
/fish.php?id=anything But would it block?: en/fish
en/fish.html
en/fish/salmon.html
en/fishheads
en/fishheads/yummy.html
**en/fish.php?id=anything (taken from Robots.txt Specifications)** I'm hoping it actually wont match, that way writing this particular robots.txt will be much easier! As basically I'm wanting to block many URL that have BTS- in such as: http://www.example.com/BTS-something
http://www.example.com/BTS-somethingelse
http://www.example.com/BTS-thingybob But have other pages that I do not want blocked, in subfolders that also have BTS- in, such as: http://www.example.com/somesubfolder/BTS-thingy
http://www.example.com/anothersubfolder/BTS-otherthingy Thanks for listening0 -
Should I use rel=canonical on similar product pages.
I'm thinking of using rel=canonical for similar products on my site. Say I'm selling pens and they are al very similar. I.e. a big pen in blue, a pack of 5 blue bic pens, a pack of 10, 50, 100 etc. should I rel=canonical them all to the best seller as its almost impossible to make the pages unique. (I realise the best I realise these should be attributes and not products but I'm sure you get my point) It seems sensible to have one master canonical page for bic pens on a site that has a great description video content and good images plus linked articles etc rather than loads of duplicate looking pages. love to hear thoughts from the Moz community.
Intermediate & Advanced SEO | | mark_baird0 -
Meta Keywords: Should we use them or not?
I am working through our site and see that meta keywords are being used heavily and unnecessarily. Each of our info pages will have 2 or 3 keyword phrases built into them. Should we just duplicate the keyword phrases into the meta keyword field, should put in additional keywords beyond or not use it at all? Thoughts and opinions appreciated
Intermediate & Advanced SEO | | Towelsrus1 -
Blocking Pages Via Robots, Can Images On Those Pages Be Included In Image Search
Hi! I have pages within my forum where visitors can upload photos. When they upload photos they provide a simple statement about the photo but no real information about the image,definitely not enough for the page to be deemed worthy of being indexed. The industry however is one that really leans on images and having the images in Google Image search is important to us. The url structure is like such: domain.com/community/photos/~username~/picture111111.aspx I wish to block the whole folder from Googlebot to prevent these low quality pages from being added to Google's main SERP results. This would be something like this: User-agent: googlebot Disallow: /community/photos/ Can I disallow Googlebot specifically rather than just using User-agent: * which would then allow googlebot-image to pick up the photos? I plan on configuring a way to add meaningful alt attributes and image names to assist in visibility, but the actual act of blocking the pages and getting the images picked up... Is this possible? Thanks! Leona
Intermediate & Advanced SEO | | HD_Leona0