Skip to content
    Moz logo Menu open Menu close
    • Products
      • Moz Pro
      • Moz Pro Home
      • Moz Local
      • Moz Local Home
      • STAT
      • Moz API
      • Moz API Home
      • Compare SEO Products
      • Moz Data
    • Free SEO Tools
      • Domain Analysis
      • Keyword Explorer
      • Link Explorer
      • Competitive Research
      • MozBar
      • More Free SEO Tools
    • Learn SEO
      • Beginner's Guide to SEO
      • SEO Learning Center
      • Moz Academy
      • MozCon
      • Webinars, Whitepapers, & Guides
    • Blog
    • Why Moz
      • Digital Marketers
      • Agency Solutions
      • Enterprise Solutions
      • Small Business Solutions
      • The Moz Story
      • New Releases
    • Log in
    • Log out
    • Products
      • Moz Pro

        Your all-in-one suite of SEO essentials.

      • Moz Local

        Raise your local SEO visibility with complete local SEO management.

      • STAT

        SERP tracking and analytics for enterprise SEO experts.

      • Moz API

        Power your SEO with our index of over 44 trillion links.

      • Compare SEO Products

        See which Moz SEO solution best meets your business needs.

      • Moz Data

        Power your SEO strategy & AI models with custom data solutions.

      Track AI Overviews in Keyword Research
      Moz Pro

      Track AI Overviews in Keyword Research

      Try it free!
    • Free SEO Tools
      • Domain Analysis

        Get top competitive SEO metrics like DA, top pages and more.

      • Keyword Explorer

        Find traffic-driving keywords with our 1.25 billion+ keyword index.

      • Link Explorer

        Explore over 40 trillion links for powerful backlink data.

      • Competitive Research

        Uncover valuable insights on your organic search competitors.

      • MozBar

        See top SEO metrics for free as you browse the web.

      • More Free SEO Tools

        Explore all the free SEO tools Moz has to offer.

      NEW Keyword Suggestions by Topic
      Moz Pro

      NEW Keyword Suggestions by Topic

      Learn more
    • Learn SEO
      • Beginner's Guide to SEO

        The #1 most popular introduction to SEO, trusted by millions.

      • SEO Learning Center

        Broaden your knowledge with SEO resources for all skill levels.

      • On-Demand Webinars

        Learn modern SEO best practices from industry experts.

      • How-To Guides

        Step-by-step guides to search success from the authority on SEO.

      • Moz Academy

        Upskill and get certified with on-demand courses & certifications.

      • MozCon

        Save on Early Bird tickets and join us in London or New York City

      Unlock flexible pricing & new endpoints
      Moz API

      Unlock flexible pricing & new endpoints

      Find your plan
    • Blog
    • Why Moz
      • Digital Marketers

        Simplify SEO tasks to save time and grow your traffic.

      • Small Business Solutions

        Uncover insights to make smarter marketing decisions in less time.

      • Agency Solutions

        Earn & keep valuable clients with unparalleled data & insights.

      • Enterprise Solutions

        Gain a competitive edge in the ever-changing world of search.

      • The Moz Story

        Moz was the first & remains the most trusted SEO company.

      • New Releases

        Get the scoop on the latest and greatest from Moz.

      Surface actionable competitive intel
      New Feature

      Surface actionable competitive intel

      Learn More
    • Log in
      • Moz Pro
      • Moz Local
      • Moz Local Dashboard
      • Moz API
      • Moz API Dashboard
      • Moz Academy
    • Avatar
      • Moz Home
      • Notifications
      • Account & Billing
      • Manage Users
      • Community Profile
      • My Q&A
      • My Videos
      • Log Out

    The Moz Q&A Forum

    • Forum
    • Questions
    • Users
    • Ask the Community

    Welcome to the Q&A Forum

    Browse the forum for helpful insights and fresh discussions about all things SEO.

    1. Home
    2. SEO Tactics
    3. Technical SEO
    4. Robots.txt and canonical tag

    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

    Technical SEO
    3
    7
    3474
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as question
    Log in to reply
    This topic has been deleted. Only users with question management privileges can see it.
    • seoug_2005
      seoug_2005 last edited by

      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 ?

      1 Reply Last reply Reply Quote 0
      • seoug_2005
        seoug_2005 @seoug_2005 last edited by

        Thanks Ryan for explaining things very clearly.

        1 Reply Last reply Reply Quote 0
        • RyanKent
          RyanKent @seoug_2005 last edited by

          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.

          1 Reply Last reply Reply Quote 1
          • seoug_2005
            seoug_2005 @RyanKent last edited by

            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 ?

            RyanKent seoug_2005 2 Replies Last reply Reply Quote 0
            • RyanKent
              RyanKent last edited by

              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.

              seoug_2005 1 Reply Last reply Reply Quote 1
              • seoug_2005
                seoug_2005 @Daylan last edited by

                Thanks Daylan for your quick response. I just wanted a second opinion that canonical tag will never be seen if a page is disallowed.

                1 Reply Last reply Reply Quote 0
                • Daylan
                  Daylan last edited by

                  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:

                  http://www.robotstxt.org/

                  seoug_2005 1 Reply Last reply Reply Quote 1
                  • 1 / 1
                  • First post
                    Last post

                  Got a burning SEO question?

                  Subscribe to Moz Pro to gain full access to Q&A, answer questions, and ask your own.


                  Start my free trial


                  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.

                  • See all categories

                  Related Questions

                  • AndyKubrin

                    Robots.txt allows wp-admin/admin-ajax.php

                    Hello, Mozzers!
                    I noticed something peculiar in the robots.txt used by one of my clients: Allow: /wp-admin/admin-ajax.php What would be the purpose of allowing a search engine to crawl this file?
                    Is it OK? Should I do something about it?
                    Everything else on /wp-admin/ is disallowed.
                    Thanks in advance for your help.
                    -AK:

                    Technical SEO | | AndyKubrin
                    2
                  • CREW-MARKETING

                    Quick Fix to "Duplicate page without canonical tag"?

                    When we pull up Google Search Console, in the Index Coverage section, under the category of Excluded, there is a sub-category called ‘Duplicate page without canonical tag’.  The majority of the 665 pages in that section are from a test environment. If we were to include in the robots.txt file, a wildcard to cover every URL that started with the particular root URL ("www.domain.com/host/"), could we eliminate the majority of these errors? That solution is not one of the 5 or 6 recommended solutions that the Google Search Console Help section text suggests.  It seems like a simple effective solution.  Are we missing something?

                    Technical SEO | | CREW-MARKETING
                    1
                  • bill369

                    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 | | bill369
                    0
                  • LabeliumUSA

                    Robot.txt : How to block a specific file type in several subdirectories ?

                    Hello everyone ! I need help setting up a robot.txt. I'm trying to block all pdf files in particular directories so I'm using this command. In the example below the line is blocking all .gif in the entire site. Block files of a specific file type (for example, .gif) | Disallow: /*.gif$ 2 questions : Can I use this command to specify one particular directory in which I want to block pdf files ? Will this line be recognized by googlebots ? Disallow: /fileadmin/xxxxxxx/xxx/xxxxxxx/*.pdf$ Then I realized that I would have to write as many lines as many directories there are in which I want to block pdf files. Let's say I want to block pdf files in all these 3 directories /fileadmin/directory1 /fileadmin/directory1/sub1 /fileadmin/directory1/sub1/pdf Is there a pattern-matching rule I could use to blocks access to pdf files in all subdirectories instead of writing 3x the above line for each subdirectory ? For exemple : Disallow: /fileadmin/directory1*/ Many thanks in advance for any insight you may have.

                    Technical SEO | | LabeliumUSA
                    0
                  • Kilgray

                    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 | | Kilgray
                    0
                  • zeepartner

                    Block Domain in robots.txt

                    Hi. We had some URLs that were indexed in Google from a www1-subdomain. We have now disabled the URLs (returning a 404 - for other reasons we cannot do a redirect from www1 to www) and blocked via robots.txt. But the amount of indexed pages keeps increasing (for 2 weeks now). Unfortunately, I cannot install Webmaster Tools for this subdomain to tell Google to back off... Any ideas why this could be and whether it's normal? I can send you more domain infos by personal message if you want to have a look at it.

                    Technical SEO | | zeepartner
                    0
                  • MagicDude4Eva

                    Duplicate title-tags with pagination and canonical

                    Some time back we implemented the Google recommendation for pagination (the rel="next/prev"). GWMT now reports 17K pages with duplicate title-tags (we have about 1,1m products on our site and about 50m pages indexed in Google) As an example we have properties listed in various states and the category title would be "Properties for Sale in [state-name]". A paginated search page or browsing a category (see also http://searchengineland.com/implementing-pagination-attributes-correctly-for-google-114970) would then include the following: The title for each page is the same - so to avoid the duplicate title-tags issue, I would think one would have the following options: Ignore what Google says Change the canonical to http://www.site.com/property/state.html (which would then only show the first XX results) Append a page number to the title "Properties for Sale in [state-name] | Page XX" Have all paginated pages use noindex,follow - this would then result in no category page being indexed Would you have the canonical point to the individual paginated page or the base page?

                    Technical SEO | | MagicDude4Eva
                    2
                  • BistosAmerica

                    Oh no googlebot can not access my robots.txt file

                    I just receive a n error message from google webmaster Wonder it was something to do with Yoast plugin. Could somebody help me with troubleshooting this? Here's original message Over the last 24 hours, Googlebot encountered 189 errors while attempting to access your robots.txt. To ensure that we didn't crawl any pages listed in that file, we postponed our crawl. Your site's overall robots.txt error rate is 100.0%. Recommended action If the site error rate is 100%: Using a web browser, attempt to access http://www.soobumimphotography.com//robots.txt. If you are able to access it from your browser, then your site may be configured to deny access to googlebot. Check the configuration of your firewall and site to ensure that you are not denying access to googlebot. If your robots.txt is a static page, verify that your web service has proper permissions to access the file. If your robots.txt is dynamically generated, verify that the scripts that generate the robots.txt are properly configured and have permission to run. Check the logs for your website to see if your scripts are failing, and if so attempt to diagnose the cause of the failure. If the site error rate is less than 100%: Using Webmaster Tools, find a day with a high error rate and examine the logs for your web server for that day. Look for errors accessing robots.txt in the logs for that day and fix the causes of those errors. The most likely explanation is that your site is overloaded. Contact your hosting provider and discuss reconfiguring your web server or adding more resources to your website. After you think you've fixed the problem, use Fetch as Google to fetch http://www.soobumimphotography.com//robots.txt to verify that Googlebot can properly access your site.

                    Technical SEO | | BistosAmerica
                    0

                  Get started with Moz Pro!

                  Unlock the power of advanced SEO tools and data-driven insights.

                  Start my free trial
                  Products
                  • Moz Pro
                  • Moz Local
                  • Moz API
                  • Moz Data
                  • STAT
                  • Product Updates
                  Moz Solutions
                  • SMB Solutions
                  • Agency Solutions
                  • Enterprise Solutions
                  • Digital Marketers
                  Free SEO Tools
                  • Domain Authority Checker
                  • Link Explorer
                  • Keyword Explorer
                  • Competitive Research
                  • Brand Authority Checker
                  • Local Citation Checker
                  • MozBar Extension
                  • MozCast
                  Resources
                  • Blog
                  • SEO Learning Center
                  • Help Hub
                  • Beginner's Guide to SEO
                  • How-to Guides
                  • Moz Academy
                  • API Docs
                  About Moz
                  • About
                  • Team
                  • Careers
                  • Contact
                  Why Moz
                  • Case Studies
                  • Testimonials
                  Get Involved
                  • Become an Affiliate
                  • MozCon
                  • Webinars
                  • Practical Marketer Series
                  • MozPod
                  Connect with us

                  Contact the Help team

                  Join our newsletter
                  Moz logo
                  © 2021 - 2025 SEOMoz, Inc., a Ziff Davis company. All rights reserved. Moz is a registered trademark of SEOMoz, Inc.
                  • Accessibility
                  • Terms of Use
                  • Privacy

                  Looks like your connection to Moz was lost, please wait while we try to reconnect.