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The 2021 Google Algorithm Ranking Factors

The 2021 Google Algorithm Ranking Factors Pie Chart

First Page Sage began conducting a continuous study of Google’s algorithm 12 years ago, and for the last several years has published its results publicly. As the largest SEO firm in the US, it has a sizable data set on which to base its understanding of the factors that comprise Google’s search algorithm. 

Below is the 2021 update, along with a description of each factor and a summary of changes from the past year.

2021 Google Algorithm Ranking Factors

Factor Weight
Consistent Publication of Engaging Content 26%
Keywords in Meta Title Tags 22%
Backlinks 16%
Niche Expertise 12%
Internal Links 5%
User Engagement 5%
Mobile-Friendly / Mobile-First Website 4%
Page Speed 3%
Site Security / SSL Certificate 2%
Offsite Mentions 1%
Schema Markup / Structured Data 1%
Keywords in URL 1%
Keywords in Header Tags 1%
Keywords in Meta Description Tags + 18 Other Factors 1%

Consistent Publication of Engaging Content

It’s been three years since content outpaced links as the top factor in Google’s search algorithm, and content increased its proportion in the algorithm in 2021. In the past 12 months, it’s become increasingly clear that Google tests new content to see if it responds well to the search intent of the keyword inputted. If the searchers’ behavior indicates that they’re getting their questions answered through your content, it is promoted. As a general rule, Google’s AI prizes thought leadership content produced at least twice per week.

Keywords in Meta Title Tags

Including the keywords you believe your page should rank for in the page’s title tag is a prerequisite to ranking. While this fact is obvious to any marketer with SEO experience, keyword strategy is a rigorous intellectual task that can easily take 20-30 minutes per page. It’s also worth noting that the placement and concentration of keywords within a title tag are also important. Ideally, your title tag would contain only your targeted keyword; but in reality, adding articles and adjectives around it are important for readability. 


Backlinks were the original foundation of Google’s algorithm, as laid out in the research paper that founded Google. However, in 2018, they began to lose ground to the two factors above: Consistent publication of engaging content and keywords in meta title tags. While backlinks are still a major factor in Google’s decision of where to rank a website in its search results, content should be your primary focus as it attracts links organically while being the most important ranking factor in and of itself.

Niche Expertise

In mid-2017, Google began favoring websites that act as niche experts. In this context, being a niche expert means having a hub of 10+ authoritative pages revolving around the same “nucleus” keyword. For example, the keyword “crm software” could be the nucleus keyword for a CRM company which has industry landing pages targeting “crm software for small business” “crm software for real estate” and “crm software for manufacturing”; and FAQ landing pages targeting “crm software pricing” “crm software advantages” and “best crm software 2021”. The consistency of the nucleus keyword across the pages of the website creates a kind of magnetism: the site attracts traffic from any Google search containing the nucleus keyword.

Internal Links

Google put much greater emphasis on this factor, which is often discussed alongside hubs, in 2017. The greater the concentration of pages with the same keyword in their title tags, the higher the site will rank for that keyword, as long as there are internal links connecting them. Publishing 100 articles on different aspects of a subject and linking all of them back to one authoritative page would be a powerful expression of that page’s value, and would confer higher ranking ability onto that page.

Note: The most comprehensive and effective SEO strategy in 2021-2022 is the hub and spoke approach, which combines Keywords in Meta Title Tags, Niche Expertise, and Internal Links.

Mobile-Friendly / Mobile-First Website

If you want to reach visitors in 2021, your site needs to be easy to navigate on mobile phones and tablets. The standard used to be “mobile friendliness,” but Google has shifted to a mobile-first world, meaning it expects mobile visitors to be the primary target of your web design. Ideally, a desktop version of your website shouldn’t even exist. The site should look exactly the same on mobile and desktop: the layout should be fairly simple and the site navigation optimized for a mobile user experience.

User Engagement

The biggest change to Google’s algorithm in the last five years is user engagement, which was integrated into the ranking algorithm in 2016. Google used to be wary of giving weight to an on-site factor that could be easily manipulated by site owners. But Google’s increasingly-sophisticated technology—borrowed from the click fraud detection side of its advertising business—has made user engagement a sizable part of its algorithm. 

User engagement is related to the #1 overall factor: Consistent publication of engaging content. Engagement, which combines bounce rate, time on page, and pages per session, is a good indicator of the content’s quality. Keep in mind, however, that searches have different intents behind them, some of which indicate that the searcher wants to quickly look up a piece of information; more is not always better.

Page Speed

Google has always prized the user experience above all else, hence its investment in thousands of datacenters around the world so that it can serve search results in milliseconds. Your site should take a page from Google’s book and focus on site speed. You want pages to load as quickly as possible. With each additional second it takes for your site to load, ranking ability is lost. You can test your page speed on Google’s free PageSpeed Insights tool.

Site Security / SSL Certificate

As the web has become more central in our lives, hackers have become more sophisticated. Google’s nightmare would be serving up sites that are harmful to its searchers. As a corollary, if your domain is even vulnerable to being hacked—if, say, your site lacks an SSL certificate (indicated by the “s” at the end of “https”)—it will lose ranking ability. An SSL certificate is usually free and can be obtained from your registrar quite easily.

Offsite Mentions 

For years, there have been discussions about whether Google takes into account mentions of a website that aren’t hyperlinks. Mentioning a company is the same idea as links but without the actual linking, so why shouldn’t that mention add to a site’s credibility in Google’s algorithm? This factor, while relatively new, makes up a small but substantive portion of Google’s algorithm.

Schema Markup / Structured Data

A modern version of meta tags, schema markup is code that you can add to your website’s pages to help Google serve more visual search results such as snippets. If you’ve ever seen search results that are longer and list out a site’s main pages; or highlight an important piece of data; or contain a 5-star ranking system or list of events, then you’re familiar with schema markup. Google favors pages that use schema markup because it makes those pages’ search results more useful to searchers. As a bonus, they also cause search results to stand out from the rest of the others on the page.

Keywords in URL

A remnant of old-school SEO from the 2000s, putting the keyword(s) you’re targeting in the URL of the page is still a best practice, although its weight in the algorithm is minimal.

Keywords in Header Tags

Including keywords in a page’s H1, H2, and H3 tags is a best practice that makes a small difference in a page’s ranking ability. You shouldn’t overdo this practice, but it’s worth keeping in mind. 

Keywords in Meta Description Tags + 18 Other Factors

There are 19 other factors that our team has observed make some difference in a site and/or page’s ability to rank. Although a website that is battling a competitor to move from the #2 spot to the #1 should be looking at every opportunity to improve, the majority of marketers don’t need to think too hard about them.

Changes in Google’s Algorithm Since 2020

The main changes that Google made to its algorithm in 2021 that differ from 2020 are as follows: 

  • The #1 factor, consistent publication of engaging content, edged up in importance by one percentage point
  • Whereas previously, the concept of creating hubs of interlinked pages focused on the same keyword was tied into Consistent Publication of Engaging Content, Keywords in Meta Title Tags, and Internal Links, this year it warrants its own category: Niche Expertise
  • Mobile-friendliness lost one percentage point, mostly because Google assumes mobile-friendliness and now only penalizes sites that have made no efforts in this area
  • Keywords in meta titles increased by one percentage point, further cementing the importance of a well-thought-out keyword strategy that responds to visitors’ search intent
  • Social signals continued their decline, seemingly counterintuitively. Our team believes this is because Google tracks so much data about its users that it doesn’t need to rely on social data as much as it once expected


The complex program that Google’s algorithm once was has settled into a shorter list of factors that require attention but not obsession. Owing to its continued eradication of low-quality SEO—an effort that first took shape in 2009 and is now all but complete—Google is much better able to fulfill its mission of creating the best possible search experience for its users by serving those users fast, relevant, and high-quality search results. What this means for marketers is that you must have a system around SEO and content production that is both organized and intentional, with each post targeting a different keyword that a member of your target audience would search. Each post should be the best treatment of the subject you can possibly deliver. From there, links, mentions, high engagement, and other important algorithm factors should accrue in your favor.

Evan Bailyn

Evan Bailyn is a best-selling author and award-winning speaker on the subjects of SEO and thought leadership. Contact Evan here.