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
-
Does Google read dynamic canonical tags?
Does Google recognize rel=canonical tag if loaded dynamically via javascript? Here's what we're using to load: <script> //Inject canonical link into page head if (window.location.href.indexOf("/subdirname1") != -1) { canonicalLink = window.location.href.replace("/kapiolani", ""); } if (window.location.href.indexOf("/subdirname2") != -1) { canonicalLink = window.location.href.replace("/straub", ""); } if (window.location.href.indexOf("/subdirname3") != -1) { canonicalLink = window.location.href.replace("/pali-momi", ""); } if (window.location.href.indexOf("/subdirname4") != -1) { canonicalLink = window.location.href.replace("/wilcox", ""); } if (canonicalLink != window.location.href) { var link = document.createElement('link'); link.rel = 'canonical'; link.href = canonicalLink; document.head.appendChild(link); } script>
Technical SEO | | SoulSurfer80 -
Blocked jquery in Robots.txt, Any SEO impact?
I've heard that Google is now indexing links and stuff available in javascript and jquery. My webmastertools is showing that some links are blocked in robots.txt of jquery. Sorry I'm not a developer or designer. I want to know is there any impact of this on my SEO? and also how can I unblock it for the robots? Check this screenshot: http://i.imgur.com/3VDWikC.png
Technical SEO | | hammadrafique0 -
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 | | zeepartner0 -
Isnt it better to have headlines in H1 and H2 tags instead of p tags?
I am working with a simple site http://http://lightsigns.com/Uniko_Manufacturing_Limited.html They seek more SEO traffic. However, the two big headlines that read "Wholesale Supply to the Sign and Display Industries" which is on line 241 and 242 of the source code, its in a p tag, i.e. <p <span class="webkit-html-tag">style</p <span>="padding-top: 0pt; " class="paragraph_style_1">Wholesale Supply to the and <p <span class="webkit-html-tag">style</p <span>="padding-bottom: 0pt; " class="paragraph_style_1">Sign and Display Industries Likewise, the product titles are in p tags, also. For example, on the Slide-in Light Box product page, http://lightsigns.com/Slide_In_light_box.html , I have done keyword research and no one is using the words slide in light box.Plus, it is also a p tag, ie. line 43 reads style="padding-bottom: 0pt; padding-top: 0pt; " class="paragraph_style">Slide-in Light Box If I suggest that they make an H2 tag with SEO-optimized keywords such as Display Light Box - Slide-In LIght Box, would this indeed help SEO? In summary, is it correct to say that H1 and H2 tags are stronger signals to the search bots of what the page is about?
Technical SEO | | BridgetGibbons1 -
Will an XML sitemap override a robots.txt
I have a client that has a robots.txt file that is blocking an entire subdomain, entirely by accident. Their original solution, not realizing the robots.txt error, was to submit an xml sitemap to get their pages indexed. I did not think this tactic would work, as the robots.txt would take precedent over the xmls sitemap. But it worked... I have no explanation as to how or why. Does anyone have an answer to this? or any experience with a website that has had a clear Disallow: / for months , that somehow has pages in the index?
Technical SEO | | KCBackofen0 -
I accidentally blocked Google with Robots.txt. What next?
Last week I uploaded my site and forgot to remove the robots.txt file with this text: User-agent: * Disallow: / I dropped from page 11 on my main keywords to past page 50. I caught it 2-3 days later and have now fixed it. I re-imported my site map with Webmaster Tools and I also did a Fetch as Google through Webmaster Tools. I tweeted out my URL to hopefully get Google to crawl it faster too. Webmaster Tools no longer says that the site is experiencing outages, but when I look at my blocked URLs it still says 249 are blocked. That's actually gone up since I made the fix. In the Google search results, it still no longer has my page title and the description still says "A description for this result is not available because of this site's robots.txt – learn more." How will this affect me long-term? When will I recover my rankings? Is there anything else I can do? Thanks for your input! www.decalsforthewall.com
Technical SEO | | Webmaster1230 -
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 | | BistosAmerica0 -
Is blocking RSS Feeds with robots.txt necessary?
Is it necessary to block an rss feed with robots.txt? It seems they are automatically not indexed (http://googlewebmastercentral.blogspot.com/2007/12/taking-feeds-out-of-our-web-search.html) And, google says here that it's important not to block RSS feeds (http://googlewebmastercentral.blogspot.com/2009/10/using-rssatom-feeds-to-discover-new.html) I'm just checking!
Technical SEO | | nicole.healthline0