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
-
Is it best practice to have a canonical tags on all pages
The website I'm working on has no canonical tags. There is duplicate content so rel=canonicals need adding to certain pages but is it best practice to have a tag on every page ?
Intermediate & Advanced SEO | | ColesNathan0 -
Canonical Chain
This is quite advanced so maybe Rand can give me an answer? I often have seen questions surrounding a 301 chain where only 85% of the link juice is passed on to the first target and 85% of that to the next one, up to three targets. But how about a canonical chain? What do I mean by this:? I have a client who sells lighting so I will use a real example (sans domain) I don't want 'new-product' pages appearing in SERPS. They dilute link equity for the categories they replicate and often contain identical products to the main categories and subcategories. I don't want to no index them all together I'd rather tell Google they are the same as the higher category/sub category. (discussion whether a noindex/follow tag would be better?) If I canonicalize new-products/ceiling-lights-c1/kitchen-lighting-c17/kitchen-ceiling-lights-c217 to /ceiling-lights-c1/kitchen-lighting-c17/kitchen-ceiling-lights-c217 I then subsequently discover that everything in kitchen-ceiling-lights-c217 is already in /kitchen-lighting-c17 and I decide to canonicalize those two - so I place a /kitchen-lighting-c17 canonical on /kitchen-ceiling-lights-c217. Then what happens to the new-products canonical? Is it the same rule - does it pass 85% of link equity back to the non new-product URL and 85% of that back to the category? does it just not work? or should I do noindexi/follow Now before you jump in: Let's assume these are done over a period of time because the obvious answer is: Canonicalize both back to /ceiling-lights-c1/kitchen-lighting-c17 I know that and that is not what I am asking. What if they are done in a sequence what is the real result? I don't want to patronise anyone but please read this carefully before giving an answer. Regards Nigel Carousel Projects.
Intermediate & Advanced SEO | | Nigel_Carr0 -
What do you add to your robots.txt on your ecommerce sites?
We're looking at expanding our robots.txt, we currently don't have the ability to noindex/nofollow. We're thinking about adding the following: Checkout Basket Then possibly: Price Theme Sortby other misc filters. What do you include?
Intermediate & Advanced SEO | | ThomasHarvey0 -
Is their value in linking to PPC landing pages and using rel="canonical"
I have ppc landing pages that are similar to my seo page. The pages are shorter with less text with a focus on converting visitors further along in the purchase cycle. My questions are: 1. Is there a benefit for having the orphan ppc pages indexed or should I no index them? 2. If indexing does provide benefits, should I create links from my site to the ppc pages or should I just submit them in a sitemap? 3. If indexed, should I use rel="canonical" and point the ppc versions to the appropriate organic page? Thanks,
Intermediate & Advanced SEO | | BrandExpSteve0 -
Avoiding Duplicate Content with Used Car Listings Database: Robots.txt vs Noindex vs Hash URLs (Help!)
Hi Guys, We have developed a plugin that allows us to display used vehicle listings from a centralized, third-party database. The functionality works similar to autotrader.com or cargurus.com, and there are two primary components: 1. Vehicle Listings Pages: this is the page where the user can use various filters to narrow the vehicle listings to find the vehicle they want.
Intermediate & Advanced SEO | | browndoginteractive
2. Vehicle Details Pages: this is the page where the user actually views the details about said vehicle. It is served up via Ajax, in a dialog box on the Vehicle Listings Pages. Example functionality: http://screencast.com/t/kArKm4tBo The Vehicle Listings pages (#1), we do want indexed and to rank. These pages have additional content besides the vehicle listings themselves, and those results are randomized or sliced/diced in different and unique ways. They're also updated twice per day. We do not want to index #2, the Vehicle Details pages, as these pages appear and disappear all of the time, based on dealer inventory, and don't have much value in the SERPs. Additionally, other sites such as autotrader.com, Yahoo Autos, and others draw from this same database, so we're worried about duplicate content. For instance, entering a snippet of dealer-provided content for one specific listing that Google indexed yielded 8,200+ results: Example Google query. We did not originally think that Google would even be able to index these pages, as they are served up via Ajax. However, it seems we were wrong, as Google has already begun indexing them. Not only is duplicate content an issue, but these pages are not meant for visitors to navigate to directly! If a user were to navigate to the url directly, from the SERPs, they would see a page that isn't styled right. Now we have to determine the right solution to keep these pages out of the index: robots.txt, noindex meta tags, or hash (#) internal links. Robots.txt Advantages: Super easy to implement Conserves crawl budget for large sites Ensures crawler doesn't get stuck. After all, if our website only has 500 pages that we really want indexed and ranked, and vehicle details pages constitute another 1,000,000,000 pages, it doesn't seem to make sense to make Googlebot crawl all of those pages. Robots.txt Disadvantages: Doesn't prevent pages from being indexed, as we've seen, probably because there are internal links to these pages. We could nofollow these internal links, thereby minimizing indexation, but this would lead to each 10-25 noindex internal links on each Vehicle Listings page (will Google think we're pagerank sculpting?) Noindex Advantages: Does prevent vehicle details pages from being indexed Allows ALL pages to be crawled (advantage?) Noindex Disadvantages: Difficult to implement (vehicle details pages are served using ajax, so they have no tag. Solution would have to involve X-Robots-Tag HTTP header and Apache, sending a noindex tag based on querystring variables, similar to this stackoverflow solution. This means the plugin functionality is no longer self-contained, and some hosts may not allow these types of Apache rewrites (as I understand it) Forces (or rather allows) Googlebot to crawl hundreds of thousands of noindex pages. I say "force" because of the crawl budget required. Crawler could get stuck/lost in so many pages, and my not like crawling a site with 1,000,000,000 pages, 99.9% of which are noindexed. Cannot be used in conjunction with robots.txt. After all, crawler never reads noindex meta tag if blocked by robots.txt Hash (#) URL Advantages: By using for links on Vehicle Listing pages to Vehicle Details pages (such as "Contact Seller" buttons), coupled with Javascript, crawler won't be able to follow/crawl these links. Best of both worlds: crawl budget isn't overtaxed by thousands of noindex pages, and internal links used to index robots.txt-disallowed pages are gone. Accomplishes same thing as "nofollowing" these links, but without looking like pagerank sculpting (?) Does not require complex Apache stuff Hash (#) URL Disdvantages: Is Google suspicious of sites with (some) internal links structured like this, since they can't crawl/follow them? Initially, we implemented robots.txt--the "sledgehammer solution." We figured that we'd have a happier crawler this way, as it wouldn't have to crawl zillions of partially duplicate vehicle details pages, and we wanted it to be like these pages didn't even exist. However, Google seems to be indexing many of these pages anyway, probably based on internal links pointing to them. We could nofollow the links pointing to these pages, but we don't want it to look like we're pagerank sculpting or something like that. If we implement noindex on these pages (and doing so is a difficult task itself), then we will be certain these pages aren't indexed. However, to do so we will have to remove the robots.txt disallowal, in order to let the crawler read the noindex tag on these pages. Intuitively, it doesn't make sense to me to make googlebot crawl zillions of vehicle details pages, all of which are noindexed, and it could easily get stuck/lost/etc. It seems like a waste of resources, and in some shadowy way bad for SEO. My developers are pushing for the third solution: using the hash URLs. This works on all hosts and keeps all functionality in the plugin self-contained (unlike noindex), and conserves crawl budget while keeping vehicle details page out of the index (unlike robots.txt). But I don't want Google to slap us 6-12 months from now because it doesn't like links like these (). Any thoughts or advice you guys have would be hugely appreciated, as I've been going in circles, circles, circles on this for a couple of days now. Also, I can provide a test site URL if you'd like to see the functionality in action.0 -
Wildcard Redirects & Canonical Tags
I have an interesting situation. Current URLs Example1: www.domain.com/red-widgets-cid-1234.html
Intermediate & Advanced SEO | | NakulGoyal
www.domain.com/red-widgets-cid-1234-1.html
www.domain.com/red-widgets-cid-1234-1-1.html Canonical on All Above URLs:
www.domain.com/red-widgets-cid-1234.html New URL:
www.domain.com/red-widgets-cid-4567.html Current URLs Example2: www.domain.com/red-widgets-cid-1234+10.html
www.domain.com/red-widgets-cid-1234+10-1.html
www.domain.com/red-widgets-cid-1234+10-1-1.html Canonical on All Above URLs:
www.domain.com/red-widgets-cid-1234+10.html New URL:
www.domain.com/red-widgets-cid-6789.html Current URLs Example3: www.domain.com/red-widgets-cid-1234+10+5.html
www.domain.com/red-widgets-cid-1234+10+5-1.html
www.domain.com/red-widgets-cid-1234+10+5-1-1.html Canonical on All Above URLs:
www.domain.com/red-widgets-cid-1234+10+5.html New URL:
www.domain.com/american-red-widgets-cid-6789+5.html I want to make sure all variations of the above URL redirect to the new URLs. However, as you see in Example 3, we are dealing with variables that are passed on. (+5 in this case). Question 1: What wildcard 301 redirect / regular expression can I use to tackle these ? Question 2: If we redirect www.domain.com/red-widgets-cid-1234+10+5.html to www.domain.com/red-widgets-cid-6789+5.html and www.domain.com/red-widgets-cid-6789+5.html contains the canonical tag www.domain.com/american-red-widgets-cid-6789+5.html, any concerns or red flags here ?0 -
Robots.txt is blocking Wordpress Pages from Googlebot?
I have a robots.txt file on my server, which I did not develop, it was done by the web designer at the company before me. Then there is a word press plugin that generates a robots.txt file. How Do I unblock all the wordpress pages from googlebot?
Intermediate & Advanced SEO | | ENSO0 -
Does Blocking ICMP Requests Affect SEO?
All in the title really. One of our clients came up with errors with a server header check, so I pinged them and it times out. The hosting company have told them that it's because they're blocking ICMP requests and this doesn't affect SEO at all... but I know that sometimes pinging posts, etc... can be beneficial so is this correct? Thanks, Steve.
Intermediate & Advanced SEO | | SteveOllington0
