For SEO, I need to have my link https://www.example.com/ on a third party website. However, I also need this website to pass parameters to my site.

If the third party website used the below structure would it pass a backlink to my main URL https://www.example.com/ or would it pass a backlink to https://www.example.com/?xyz=55

Would this be seen as legit from an SEO perspective or pushing it? Is there a better way to accomplish this from an SEO perspective?

   var val = 55;

Link to <a href="https://www.example.com/" onclick="location.href=this.href+'?xyz='+val;return false;">My Site</a>
  • I think, in your example, the main SEO perspective will be at https://www.example.com/. Additionally probably there will be some effect on https://www.example.com/?xyz=55, because Google will get transition signals from users across Chrome web browsers. Of course, only if users will click to this link.
    – Timur
    Commented Sep 26, 2021 at 7:44
  • Please consider registering your account, which will give you access to more of the site's features. Commented Sep 26, 2021 at 10:12
  • 1
    What is the purpose of this parameter? Does it change what content gets seen on your site? Commented Sep 26, 2021 at 10:12
  • @stephenostermiller, The parameter allows drop downs selections on the landing page to be prefilled when the user arrives at https://www.example.com/?xyz=55 versus user would have to complete drop down selections when arriving at https://www.example.com Commented Sep 26, 2021 at 18:39
  • 1
    @user1609391 don't use robots.txt for this, it's a bad idea and bad for SEO. Use rel="canonical" link tag, if these parameters only pre-filling the drop downs selections.
    – Timur
    Commented Sep 27, 2021 at 5:30

2 Answers 2


Based on Links Crawable Guidelines, the link will be crawled as https://www.example.com/, because Google can not follow link from onclick attributes.

Google search central says:

Google can follow links only if they are an <a> tag with an href attribute. Links that use other formats won't be followed by Google's crawlers. Google cannot follow <a> links without an href tag or other tags that perform a links because of script events. Here are examples of links that Google can and can't follow:

  • Can follow:
    • <a href="https://example.com">
    • <a href="/relative/path/file">
  • Can't follow:
    • <a routerLink="some/path">
    • <span href="https://example.com">
    • <a onclick="goto('https://example.com')">

I just saw the test that @Trebor mentioned in a comment which says The onclicks links were fully crawled and followed, but that test was created in 2015, and the official guidelines was first captured at 2020-11-11 and the last updated at 2021-08-26, so I prefer to believe in official announcements than the test. Because I think the test is outdated, I need the test that created at least this year to prove it.

I see in your comment says:

I'm thinking of blocking the parameter pages with robots.txt or in webmaster tools to prevent duplicate content and put the focus on https://www.example.com

Based on Duplicate URLs guideline, don't block pages using robots.txt, just use rel=canonical <link> tag , rel=canonical HTTP header, Sitemap, 301 redirect, or AMP variant as described at official Google guideline.

General guidelines For all canonicalization(duplicate URLs signal) methods, follow these general guidelines:

  • Don't use the robots.txt file for canonicalization purposes.

  • Don't use the URL removal tool for canonicalization. It removes all versions of a URL from Search.

  • Don't specify different URLs as canonical for the same page using the same or different canonicalization techniques (for example, don't specify one URL in a sitemap but a different URL for that same page using rel="canonical").

  • Don't use noindex as a means to prevent selection of a canonical page. This directive is intended to exclude the page from the index, not to manage the choice of a canonical page.

  • Specify a canonical page when using hreflang tags. Specify a canonical page in same language, or the best possible substitute language if a canonical doesn't exist for the same language.

  • Link to the canonical URL rather than a duplicate URL, when linking within your site. Linking consistently to the URL that you consider to be canonical helps Google understand your preference.

  • 2
    While the Google link says Google can't crawl the link according to tests done by others, searchengineland.com/…, it appears that Google is able to follow JS links, including OnClick events.
    – Trebor
    Commented Sep 26, 2021 at 14:30
  • @Trebor Nice test information, but it looks like the test is outdated. I can't trust that test because the tests was from 2015 and the official Google guidelines updated at 2021-08-26 UTC. So I need the test after that date to prove it. Commented Sep 26, 2021 at 21:08

This is a good hole for XSS-attack and very bad practice!

onclick="location.href=this.href+'?xyz='+val;return false;"

Use click trackers to track mailto and other non-HTTP calls only.

You can use something like this:

<a href="http://example.com" target="_blank" rel="noopener">


the transfer of the link juice will depend on the processing settings for the "?"-parameter on your web server, in Google SearchConsole and robots.txt

  • Thank you, interesting on the xss attack. In this use the parameter is never a result of user input. My partner's website will assign the parameter server side and redirect to my site with the parameter. In this use is it still vulnerable to xss? If so could you help me understand how? Commented Sep 28, 2021 at 3:03

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