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
-
Canonical and Alternate Advice
At the moment for most of our sites, we have both a desktop and mobile version of our sites. They both show the same content and use the same URL structure as each other. The server determines whether if you're visiting from either device and displays the relevant version of the site. We are in a predicament of how to properly use the canonical and alternate rel tags. Currently we have a canonical on mobile and alternate on desktop, both of which have the same URL because both mobile and desktop use the same as explained in the first paragraph. Would the way of us doing it at the moment be correct?
Intermediate & Advanced SEO | | JH_OffLimits3 -
Should I use the on classified listing pages that have expired?
We have went back and forth on this and wanted to get some outside input. I work for an online listing website that has classified ads on it. These ads are generated by companies on our site advertising weekend events around the country. We have about 10,000 companies that use our service to generate their online ads. This means that we have thousands of pages being created each week. The ads have lots of content: pictures, sale descriptions, and company information. After the ads have expired, and the sale is no longer happening, we are currently placing the in the heads of each page. The content is not relative anymore since the ad has ended. The only value the content offers a searcher is the images (there are millions on expired ads) and the descriptions of the items for sale. We currently are the leader in our industry and control most of the top spots on Google for our keywords. We have been worried about cluttering up the search results with pages of ads that are expired. In our Moz account right now we currently have over 28k crawler warnings alerting us to the being in the page heads of the expired ads. Seeing those warnings have made us nervous and second guessing what we are doing. Does anybody have any thoughts on this? Should we continue with placing the in the heads of the expired ads, or should we be allowing search engines to index the old pages. I have seen websites with discontinued products keeping the products around so that individuals can look up past information. This is the closest thing have seen to our situation. Any help or insight would be greatly appreciated! -Matt
Intermediate & Advanced SEO | | mellison0 -
Large robots.txt file
We're looking at potentially creating a robots.txt with 1450 lines in it. This will remove 100k+ pages from the crawl that are all old pages (I know, the ideal would be to delete/noindex but not viable unfortunately) Now the issue i'm thinking is that a large robots.txt will either stop the robots.txt from being followed or will slow our crawl rate down. Does anybody have any experience with a robots.txt of that size?
Intermediate & Advanced SEO | | ThomasHarvey0 -
Using hreflang="en" instead of hreflang="en-gb"
Hello, I have a question in regard to international SEO and the hreflang meta tag. We are currently a B2B business in the UK. Our major market is England with some exceptions of sales internationally. We are wanting to increase our ranking into other english speaking countries and regions such as Ireland and the Channel Islands. My research has found regional google search engines for Ireland (google.ie), Jersey (google.je) and Guernsey (google.gg). Now, all the regions have English as one their main language and here is my questions. Because I use hreflang=“en-gb” as my site language, am I regional excluding these countries and islands? If I used hreflang=“en” would it include these english speaking regions and possible increase the ranking on these the regional search engines? Thank you,
Intermediate & Advanced SEO | | SilverStar11 -
Is it a problem to use a 301 redirect to a 404 error page, instead of serving directly a 404 page?
We are building URLs dynamically with apache rewrite.
Intermediate & Advanced SEO | | lcourse
When we detect that an URL is matching some valid patterns, we serve a script which then may detect that the combination of parameters in the URL does not exist. If this happens we produce a 301 redirect to another URL which serves a 404 error page, So my doubt is the following: Do I have to worry about not serving directly an 404, but redirecting (301) to a 404 page? Will this lead to the erroneous original URL staying longer in the google index than if I would serve directly a 404? Some context. It is a site with about 200.000 web pages and we have currently 90.000 404 errors reported in webmaster tools (even though only 600 detected last month).0 -
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 -
Canonical URLs and Sitemaps
We are using canonical link tags for product pages in a scenario where the URLs on the site contain category names, and the canonical URL points to a URL which does not contain the category names. So, the product page on the site is like www.example.com/clothes/skirts/skater-skirt-12345, and also like www.example.com/sale/clearance/skater-skirt-12345 in another category. And on both of these pages, the canonical link tag references a 3rd URL like www.example.com/skater-skirt-12345. This 3rd URL, used in the canonical link tag is a valid page, and displays the same content as the other two versions, but there are no actual links to this generic version anywhere on the site (nor external). Questions: 1. Does the generic URL referenced in the canonical link also need to be included as on-page links somewhere in the crawled navigation of the site, or is it okay to be just a valid URL not linked anywhere except for the canonical tags? 2. In our sitemap, is it okay to reference the non-canonical URLs, or does the sitemap have to reference only the canonical URL? In our case, the sitemap points to yet a 3rd variation of the URL, like www.example.com/product.jsp?productID=12345. This page retrieves the same content as the others, and includes a canonical link tag back to www.example.com/skater-skirt-12345. Is this a valid approach, or should we revise the sitemap to point to either the category-specific links or the canonical links?
Intermediate & Advanced SEO | | 379seo0 -
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