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.
Robots.txt and canonical tag
-
In the SEOmoz post - http://www.seomoz.org/blog/robot-access-indexation-restriction-techniques-avoiding-conflicts, it's being said -
If you have a robots.txt disallow in place for a page, the canonical tag will never be seen.
Does it so happen that if a page is disallowed by robots.txt, spiders DO NOT read the html code ?
-
Thanks Ryan for explaining things very clearly.
-
What we know is there have been many cases where a page that is blocked in robots.txt has appeared in search results. The explanation provided is that robots.txt blocks crawlers during normal site visits, but not necessarily on visits where they are following links from other sites.
-
If spiders follow links to an article on my site, will they read the contents then ? If the canonical tag is on article page itself, will canonical tag will be seen ?
-
Daylan offered a great answer but I would like to add one exception. When crawlers from the major SEs visit your site they will honor your robots.txt file but sometimes they will follow links from other sites to an article on your site, and during that particular visit they will not see the robots.txt file and index your page.
This is one of the reasons why your robots.txt file should be used as minimally as possible, and when it is used you should have a backup process in place such as the canonical or noindex tag on a page.
-
Thanks Daylan for your quick response. I just wanted a second opinion that canonical tag will never be seen if a page is disallowed.
-
Thats correct in most cases:
It works likes this: a robot wants to vists a Web site URL, say http://www.example.com/welcome.html. Before it does so, it firsts checks for http://www.example.com/robots.txt, and finds:
User-agent: *
Disallow: /The "User-agent: *" means this section applies to all robots. The "Disallow: /" tells the robot that it should not visit any pages on the site.
Robots can ignore your /robots.txt. Especially malware robots that scan the web for security vulnerabilities, and email address harvesters used by spammers will pay no attention.
More information available here about:
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
-
I have two robots.txt pages for www and non-www version. Will that be a problem?
There are two robots.txt pages. One for www version and another for non-www version though I have moved to the non-www version.
Technical SEO | | ramb0 -
Crawl solutions for landing pages that don't contain a robots.txt file?
My site (www.nomader.com) is currently built on Instapage, which does not offer the ability to add a robots.txt file. I plan to migrate to a Shopify site in the coming months, but for now the Instapage site is my primary website. In the interim, would you suggest that I manually request a Google crawl through the search console tool? If so, how often? Any other suggestions for countering this Meta Noindex issue?
Technical SEO | | Nomader1 -
Do Canonical Tags Pass Link Juice?
I have an ecommerce website where some pages link to a product page with a different URL. EXAMPLE: 1: /category/product1.html (not indexed by Google) with canonical pointing to product1.html Other page link to the product like below. 2: product1.html (indexed by Google) Now the question is, does 1: pass any link juice to product1.html or not? Is it worth to change everything and link only to one URL? My site is running on Magento!
Technical SEO | | bill3690 -
Can I set a canonical tag to an anchor link?
I have a client who is moving to a one page website design. So, content from the inner pages is being condensed in to sections on the 'home' page. There will be a navigation that anchor links to each relevant section. I am wondering if I should leave the old pages and use rel=canonical to point them to their relevant sections on the new 'home' page rather than 301 them. Thoughts?
Technical SEO | | Vizergy0 -
Robots txt. in page with 301 redirect
We currently have a a series of help pages that we would like to disallow from our robots txt. The thing is that these help pages are located in our old website, which now has a 301 redirect to current site. Which is the proper way to go around? 1- Add the pages we want to disallow to the robots.txt of the new website? 2- Break the redirect momentarily and add the pages to the robots.txt of the old one? Thanks
Technical SEO | | Kilgray0 -
Geotargeting duplicate content to different regions - href and canonical tag confusion
If you duplicate content onto a sub-folder for say a new US geotargeted site (to target kw spelling differences) and, in addition to GWT geotargeting settings, implement the 'Canonical' and 'Hreflang' tags on these new pages to show G different region and language version (en-us). Then does the original/main site similar pages also need to have canonical and href tags ? The main/original sites page I don't really want to target a specific country (although existing signals (hosting etc) will be UK (primary target of main site) but pages show up in other country searches too (which we want). Im presuming fine to leave the original/main site as it currently is although wording in google blog/webmaster central articles etc are a bit confusing hence why im asking for anyone elses opinion/input on this. Also is there are any benefit (or just best practice) to use 'www.example.com/en-us/...' in the subdirectory URL as opposed to just 'www.example.com/us/' many thanks in advance to any commentators 🙂
Technical SEO | | Dan-Lawrence0 -
Internal search : rel=canonical vs noindex vs robots.txt
Hi everyone, I have a website with a lot of internal search results pages indexed. I'm not asking if they should be indexed or not, I know they should not according to Google's guidelines. And they make a bunch of duplicated pages so I want to solve this problem. The thing is, if I noindex them, the site is gonna lose a non-negligible chunk of traffic : nearly 13% according to google analytics !!! I thought of blocking them in robots.txt. This solution would not keep them out of the index. But the pages appearing in GG SERPS would then look empty (no title, no description), thus their CTR would plummet and I would lose a bit of traffic too... The last idea I had was to use a rel=canonical tag pointing to the original search page (that is empty, without results), but it would probably have the same effect as noindexing them, wouldn't it ? (never tried so I'm not sure of this) Of course I did some research on the subject, but each of my finding recommanded one of the 3 methods only ! One even recommanded noindex+robots.txt block which is stupid because the noindex would then be useless... Is there somebody who can tell me which option is the best to keep this traffic ? Thanks a million
Technical SEO | | JohannCR0 -
URL query strings and canonical tag
Hi, I have recently been getting my comparison website redesigned and developed onto wordpress and the site is now 90% complete. Part of the redesign has meant that there are now dynamic urls in the format: http://www.mywebsite.com/10-pounds-productss/?display=cost&value=10 I have other pages similar to this but with different content for the different price ranges and these are linked to from the menus: http://www.mywebsite.com/20-pounds-products/?display=cost&value=20 Now my questions are: 1. I am using Joost's All-in-one SEO plugin and this adds a canonical tag to the page that is pointing to http://www.mywebsite.com/10-pounds-products/ which is the permalink. Is this OK as it is or should i change this to http://www.mywebsite.com/10-pounds-products/?display=cost&value=10 2. Which URL will get indexed, what gets shown as the display URL in the SERPs and what page will users land on? I'm a bit confused so apologies if these seem like silly questions. Thanks
Technical SEO | | bizarro10000