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:
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
-
Robots.txt allows wp-admin/admin-ajax.php
Hello, Mozzers!
Technical SEO | | AndyKubrin
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:2 -
Role of Robots.txt and Search Console parameters settings
Hi, wondering if anyone can point me to resources or explain the difference between these two. If a site has url parameters disallowed in Robots.txt is it redundant to edit settings in Search Console parameters to anything other than "Let Googlebot Decide"?
Technical SEO | | LivDetrick0 -
Is sitemap required on my robots.txt?
Hi, I know that linking your sitemap from your robots.txt file is a good practice. Ok, but... may I just send my sitemap to search console and forget about adding ti to my robots.txt? That's my situation: 1 multilang platform which means... ... 2 set of pages. One for each lang, of course But my CMS (magento) only allows me to have 1 robots.txt file So, again: may I have a robots.txt file woth no sitemap AND not suffering any potential SEO loss? Thanks in advance, Juan Vicente Mañanas Abad
Technical SEO | | Webicultors0 -
Do H2 tags carry more weight than h4 tags?
Of course H tags are key signals for relevance in search. Does an h2 tag send a significantly "louder" signal than an h4 tag?
Technical SEO | | aj6130 -
Blocking Affiliate Links via robots.txt
Hi, I work with a client who has a large affiliate network pointing to their domain which is a large part of their inbound marketing strategy. All of these links point to a subdomain of affiliates.example.com, which then redirects the links through a 301 redirect to the relevant target page for the link. These links have been showing up in Webmaster Tools as top linking domains and also in the latest downloaded links reports. To follow guidelines and ensure that these links aren't counted by Google for either positive or negative impact on the site, we have added a block on the robots.txt of the affiliates.example.com subdomain, blocking search engines from crawling the full subddomain. The robots.txt file is the following code: User-agent: * Disallow: / We have authenticated the subdomain with Google Webmaster Tools and made certain that Google can reach and read the robots.txt file. We know they are being blocked from reading the affiliates subdomain. However, we added this affiliates subdomain block a few weeks ago to the robots.txt, but links are still showing up in the latest downloads report as first being discovered after we added the block. It's been a few weeks already, and we want to make sure that the block was implemented properly and that these links aren't being used to negatively impact the site. Any suggestions or clarification would be helpful - if the subdomain is being blocked for the search engines, why are the search engines following the links and reporting them in the www.example.com subdomain GWMT account as latest links. And if the block is implemented properly, will the total number of links pointing to our site as reported in the links to your site section be reduced, or does this not have an impact on that figure?From a development standpoint, it's a much easier fix for us to adjust the robots.txt file than to change the affiliate linking connection from a 301 to a 302, which is why we decided to go with this option.Any help you can offer will be greatly appreciated.Thanks,Mark
Technical SEO | | Mark_Ginsberg0 -
No indexing url including query string with Robots txt
Dear all, how can I block url/pages with query strings like page.html?dir=asc&order=name with robots txt? Thanks!
Technical SEO | | HMK-NL0 -
Invisible robots.txt?
So here's a weird one... Client comes to me for some simple changes, turns out there are some major issues with the site, one of which is that none of the correct content pages are showing up in Google, just ancillary (outdated) ones. Looks like an issue because even the main homepage isn't showing up with a "site:domain.com" So, I add to Webmaster Tools and, after an hour or so, I get the red bar of doom, "robots.txt is blocking important pages." I check it out in Webmasters and, sure enough, it's a "User agent: * Disallow /" ACK! But wait... there's no robots.txt to be found on the server. I can go to domain.com/robots.txt and see it but nothing via FTP. I upload a new one and, thankfully, that is now showing but I've never seen that before. Question is: can a robots.txt file be stored in a way that can't be seen? Thanks!
Technical SEO | | joshcanhelp0 -
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