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Google: Penalties for unnatural, outbound links

In mid-April, Google sent a warning email to operators of websites on which unnatural, deceptive, or manipulative outbound links had been detected.

This article provides tips on how you can use OnPage.org to identify and correct unnatural outbound links.

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Figure 1: Example of a notification email from Google

Although outbound links rarely change, the content of the linked websites might change over time. This could result from expired domains, sale of certain projects, hacked websites, etc. The destination page of an outbound link should provide additional information to users. In the worst case scenario, changes in the content of the linked page might end up affecting visitors of your website.

Use OnPage.org Zoom to identify potentially untrustworthy outbound content

In order to further emphasize the importance of externally linked content, "Links to potentially shady pages" are included in the KPIs under "Content" in the OnPage.org Zoom Dashboard.

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Figure 2: "shady pages" as a KPI in OnPage.org Zoom Dashboard

Clicking on this KPI directly takes you to the report with the corresponding analysis. The report detects potentially untrustworthy pages by evaluating the content of the linked pages based on certain criteria.

By default, the tool goes through the content of such websites looking for the terms "Viagra" or "casino". If one of the terms is found within the website’s text, the external page is considered potentially untrustworthy and added to the table shown below.

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Figure 3: Report showing potentially untrustworthy pages

You can also customize the standard filter and have it search the linked websites for the terms you want. To do this, click on the filter "Plaintext" to edit or add terms.

You can use different rules to customize the filter and specify conditions that should be applied when analyzing untrustworthy pages. Once you change the filter settings, the external websites are re-evaluated immediately and the new results displayed within seconds. A new crawl is not necessary.

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Figure 4: Filter options

For example, combining "contains" and "or" allows you to search for multiple terms. A website will thus be considered untrustworthy if either of the terms is detected.

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Figure 5: Contains "or" combinations

Regex is particularly ideal for advanced users and can be used in very complex applications. An example is if you need to add "and/or" combinations in the filter settings. In the above example, a website is considered untrustworthy if its content uses either "Viagra" or "casino" with either of the two terms "sex" or "porn".

Below are the possible term combinations that classify a website as untrustworthy:

  • Viagra AND sex

  • Viagra AND porn

  • Casino AND sex

  • Casino AND porn

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Figure 6: Filter settings with regex

Fix outbound links to untrustworthy websites

In addition to the external URLs, you can also view how often the external website is linked from your website. This is indicated under "Internal outbound links (counter)". Clicking on the number of links opens a list of the URLs on which the external URL is linked.

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Figure 7: Number of internal links that point to external websites

There are two ways of dealing with outbound links that point to untrustworthy websites. You can either:

In Google’s "Best practices for bloggers reviewing free products they receive from companies" article, Google advises bloggers to always use the nofollow attribute for links that result from co-operations. Generally, it is always advisable to use the nofollow attribute for user generated content (UGC), e.g., from forums or comment fields.

Use the following code to add the nofollow attribute:

<a href="http://domain.com" rel="nofollow">anchor text</a>

In cases where the content of the external website has changed a lot, it is advisable that you remove the link since redirecting the user to the website no longer makes sense.


In the future, you should always keep an eye on your website’s outbound links in order to avoid penalties. OnPage.org tools helps you identify unwanted, outbound content and promptly remove suspicious content. Advanced users can also use regex options to identify untrustworthy content. Always make sure your website is in a good neighborhood!

Happy Optimizing!

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Published on Apr 19, 2016 by Stephan Walcher