SEO & AI - What Is RankBrain

December 28, 2020 Mihaela Lica Butler

According to Google, RankBrain is “the third-most important factor for ranking webpages,” after content and links. Contrary to popular belief, it is not an algorithm per se, but part of the larger Hummingbird equation, which includes hundreds of other ranking factors and thousands of ranking sub-signals. For example, Hummingbird encompasses search filters like Panda, which identifies poor quality content; Penguin, which fights against spammy websites; and Pigeon, which delivers local results. There are many others, of course, and Google does not reveal exactly what it uses to rank search results in its SERPs. Nevertheless, a look at the “Periodic Table of SEO Success Factors” by Search Engine Land will give you a fair idea.

Periodic Table SEO Success Factors

Periodic Table SEO Success Factors

If a couple of years ago RankBrain handled only about 15% of Google’s searches, SEOs know that today it handles all of them, as Jeff Dean, the head of has confirmed in an interview in 2016.

The “super-power” of RankBrain lays in its ability to understand medium to long-tail search queries delivering the most relevant search results to the user first. It also can learn from searcher behaviours, refining these results based on geolocation and language when necessary too.

To put it simply, RankBrain eliminates the need of creating content multiple web pages based on keyword phrases targeting the same type of service or product. For example, Rand Fishkin, the founder of Moz, explained “you no longer need four pages targeting 1) kids clothing, 2) children's clothing, 3) clothes for kids, 4) clothes for children. Google knows all of those mean the same thing, and they return almost exactly the same results for all four, so you’re better off creating one page that serves that intent rather than four different ones.”

When Google announced RankBrain to the world in 2015 many voices proclaimed the death of SEO. The problem was that Gary Illyes from Google said at SMX Advanced in June 2016 that RankBrain was not assigned a score, and that:

"House Elf and Chief of Sunshine and Happiness at Google. Resident bad guy and Lizzi's parrot. Onions are my own"

But there are a few things that can improve the quality of a web page for RankBrain to consider it useful enough to deliver it in the SERPs as a response to a search query.

SEO Strategies for RankBrain

The main purpose of RankBrain is to put in front of Google search users’ relevant content they will love to read. Therefore, the best way to do SEO for RankBrain is to optimize webpages for humans and not for search engines. This implies everything from website design, to content, speed, and all the aspects visitors need and expect. Although RankBrain operates at a keyword level, it’s AI and it learns from user behaviour too. Everything that may affect negatively the user experience may harm SEO. So, first have a solid technical structure – because while RankBrain doesn’t deal with the technical aspects, it will not rank a broken site.

Take care of your technical SEO

  • HTTPS is a must – it may not be a powerful SEO ranking signal, but it matters, and it tells the users that your website is trustworthy and secure.
  • Fast side load time make the users happy – and it also matters for Google. It’s a landing page factor for Google Search and Ads and is a ranking factor for mobile searches too. Aim for a mobile speed score as close to 10 as possible. As Google puts it, a slow mobile site limits your business.
  • If you don’t have a mobile site, at least ensure that your current site is mobile-friendly. Google offers a free tool to test your site, and loads of documentation on mobile SEO to help you improve your website, especially showing you how to avoid common mistakes that frustrate mobile visitors.
  • Avoid keyword cannibalization – like targeting the same keyword or keyword phrase over multiple webpages across the same website. It may cause a less valuable and useful page to rank above the best page or drag down your rankings for both pages.
  • Avoid duplicate content – Google may penalize your site if it determines that the duplicate content was created to manipulate search engine rankings or win more traffic. If you must have duplicate pages, there are ways to signal Google why they are in place without affecting your SEO and the overall user experience in search.
  • Care for your meta descriptions – although they are not major ranking signals, titles and meta descriptions appear in SERPs when Google ranks your site. Length and duplicate errors can affect your CTR in SERPs. Plus, RankBrain may look for keywords there.
  • Implement structured data – this will enable a rich set of features for your page in search results, including Google’s enriched search results, Knowledge Graph results, and carousels. Most search structured data uses vocabulary. Google offers a free structured data testing tool that helps you check for errors and other issues.

Technical SEO has many other elements we have described in the past in detail. See our article – The Importance of Technical SEO – for reference. Implementing technical SEO fixes improves the health of a site and the user experience, which is vital in the process of optimizing websites for people.

Optimize for humans, not for search engines

To rank websites organically, Google also requires proof that users like what they see – that they read and interact with the content of a page. A study by SEMrush in 2017 identified that there is an undeniable relation between RankBrain, page session duration, and organic rankings:

“When you can make a deep personal connection user engagement will deepen with higher CTR and longer session durations,” SEO expert Jen Saunders explained in support of her theory, adding “When your newly written content mirrors user intent, you can expect to see an increase in session durations, as well as an elevated position in the SERPs.”

Over at WordStream, SEO veteran Larry Kim is another expert who is convinced that CTR and RankBrain are related. He argues that the future of SEO “isn't about beating another page based on content length, social metrics, keyword usage, or your number of backlinks. Better organic search visibility will come from beating your competitors with a higher than expected click-through rate.” This is because RankBrain does learn from what people are clicking on in search. His advice is spot on “you need to combine keywords and emotional triggers to create SEO superstorms that result in ridiculous CTRs and leave your competition devastated.”

It makes sense to identify pages that perform poorly and to improve them with better content to please your readers. To please RankBrain you should start by redefining your keyword strategy.

Rethink your keyword strategy

With RankBrain, the need for optimizing for only one keyword or keyword phrase per web page becomes obsolete. AI deals with concepts and learns fast. Google announced a conversational search experience in 2013, and it’s been dealing with natural language search queries delivering excellent results to actual questions for years now. This is the future of search and this is where optimizing for RankBrain is different than traditional SEO.

Keyword research now should focus on long-tail phrases such as those people use for smartphone voice searches. There are many free tools to use to find long-tail keyword phrases, including Google Correlate,,, SEMRush,, and others. You can also scroll down to the Google SERPs after you type in your main keyword and look at “searches related to…” to find more suggestions.

Content that creates engagement

To optimize for RankBrain, your best bet is to write for people. Keep your texts simple, conversational, and free of buzz words and colloquialisms. Incorporate your long-term keyword phrases as they would appear naturally in a conversation, without repeating them ad nauseam. Context is very important for readers and RankBrain identifies it quickly.

Incorporate FAQ sections in your site to address some of the basic customer service problems of your business and to show transparency and expertise. Your customers may need answers regarding payments and shipping – when you are upfront about these issues, you will also earn their trust.

Accessibility is another important aspect – ideally, your content should be machine-readable to satisfy website visitors with visual impairments, or those who are busy and use text-to-speech apps to listen instead of reading.

Deliver the type of content that is useful, responds to the needs of your visitors, and entertains. Think less like a marketer and more in terms of creating authentic experiences and inspiring your readers. In other words, write the type of content people want to share and talk about.

Here’s how to optimize for RankBrain straight from Google

“Optimizing for RankBrain is actually super easy, and it is something we’ve probably been saying for fifteen years now, is – and the recommendation is – to write in natural language. Try to write content that sounds human. If you try to write like a machine then RankBrain will just get confused and probably just pushes you back,” explains Google’s Gary Illyes, adding “But if you have a content site, try to read out some of your articles or whatever you wrote, and ask people whether it sounds natural. If it sounds conversational, if it sounds like natural language that we would use in your day to day life, then sure, you are optimized for RankBrain.”