Google Quality Rater Guidelines: How the Algorithm Recognises Quality

How does Google’s search algorithm assess the quality of websites? The Google Quality Evaluator Guidelines (also known as the rater guidelines) provide a framework that helps answer this question. Webmasters and SEOs can use this framework to gain a better understanding of how the algorithm operates and act accordingly.

Lily Ray talks about the Quality Rater Guidelines and why they are relevant to SEOs

Lily Ray is a member of the SISTRIX Data Journalism Team

What are the Google Quality Rater Guidelines?

The Google Quality Rater Guidelines also known as the Quality Evaluator Guidelines, provide instructions on how to evaluate the quality of websites. The aim of these recommendations is to improve the Google search algorithm and offer searchers an even better user experience. Using the Google Quality Rater Guidelines as a guide, the quality raters perform random checks to see if the websites that are displayed in the search results are relevant and helpful to users.

Where is the Quality Rater Guideline PDF?

Download the Google Quality Evaluator Guidelines here. (PDF, 17 MB, 175 pages)

What are the responsibilities of Google Quality Raters?

Quality raters are third-party contractors who assist Google in the evaluation of the websites that appear in its search results. Every year, they manually check tens of thousands of landing pages with regard to their relevance to the respective search query.

To do this, they use rating scales that are defined in the Google Quality Rater Guidelines. The work of the quality raters is the basis for the hundreds of smaller updates that constantly improve the algorithm and help ensure better-quality search results.

Which evaluation criteria are specified in Google’s Quality Rater Guidelines?

Google’s Quality Rating is divided into two main areas:

1. Page Quality (PQ): the quality of a website

There are a number of factors that are used to assess the quality of a website:

  • The goal or purpose of the website: Every website should have a goal. It does not matter what this goal is; what matters is the added value that is created for the user. So-called YMYL websites have to meet the highest quality standards. YMYL stands for “Your Money, Your Life” and refers to sites that provide information on sensitive topics, such as health and finance. If a website does not provide any added value or has the potential to cause harm to the user, it must be rated with the worst quality level.
  • Content evaluation: Google’s Quality Rater Guidelines recommend that quality raters focus on the most important content (Main Content, or MC) on the website and assess its quality, whether it be text, images or videos. The so-called Supplementary Content (SC) comprises the navigation elements, sidebars and other elements that improve the user experience. The third area relates to the monetisation of the website, such as the placement of advertisements. This is not negative per se, but such ads are judged negatively if they cover or interrupt the main content.
  • E-A-T at Google: E-A-T stands for “Expertise“, “Authoritativeness” and “Trustworthiness” – that is, expert status, authority, and trustworthiness of the source from which the information originates. These factors determine how credible the content is. They play an important role in determining a website’s ranking – and this is especially true of YMYL pages.

Sites are classified as high-quality websites if they meet these requirements:

  • A very high level of E-A-T
  • High-quality main content
  • User-friendly navigation
  • Very good reputation of the website
  • Transparency with regard to the source or the person(s) responsible for the content

2. Needs Met (NM): satisfying the needs of users.

The primary goal of the Google Quality Rater Guidelines is to meet the needs of users. The quality raters are therefore provided with examples in the Google guidelines that help them to classify the different types of search queries and assess the quality of the search results.

At the same time, they set up so-called flags in order to devalue websites that are inaccessible or include foreign-language content.


The Google Quality Rater Guidelines are updated on an ad hoc basis. They are a must-read for every webmaster or SEO who wants to optimise a website for higher rankings or gain a better understanding of how the search algorithm works. You can download the current Google quality rater guidelines here.

Steve Paine