Keyword Difficulty: How to Estimate Your Chances to Rank

Keyword Difficulty: How to Estimate Your Chances to Rank

Tim Soulo
Tim is CMO at Ahrefs. With over 15 years in the digital marketing industry, Tim is the author of many data-driven studies and actionable marketing frameworks, some of which gained industry-wide recognition. He enjoys challenging conventional marketing knowledge and optimizing for simplicity and efficiency.
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    It’s easy to find keywords that can bring lots of traffic to your website. What’s harder is to predict your chances of ranking for them.

    To help solve this problem, SEO tools like Ahrefs give keywords a “difficulty” score from 0 to 100.

    But the truth is that these scores aren’t foolproof.

    So in this post, I’m going to outline the benefits and shortcomings of the Keyword Difficulty metric, as well as break down what other things professional SEOs look at when estimating their chances to rank for a given keyword.

    What is keyword difficulty?

    Keyword Difficulty (KD) is an SEO metric that estimates how hard it would be to rank on the first page of Google for a given keyword. It is measured on a scale from 0 to 100, with the latter being the hardest to rank for.

    Keywords Explorer overview of "best backpack," which has a KD of 42

    However, when many SEO professionals use the term “keyword difficulty,” they’re referring to the broader concept of ranking difficulty—not a particular metric in a particular SEO tool.

    Keyword difficulty as a metric

    Almost every keyword research tool has a keyword difficulty score. These tools all use the same 0-100 scale, but each one calculates it differently.

    If you check the keyword difficulty of the same keywords in different SEO tools, the numbers will vary quite substantially:

    Table showing KD scores for various keywords vary for each tool

    That is why it is important to understand how exactly the ranking difficulty is calculated by your SEO tool of choice. Only then can you make informed decisions based on it.

    Here at Ahrefs, we use a simple method for calculating KD. We pull the top 10 ranking pages for your keyword and look up how many websites link to each of them. The more links the top-ranking pages for your keyword have, the higher its KD score. Very simple and very actionable.

    SERP overview for "best backpack"

    Keyword Difficulty in Ahrefs is based on linking domains to top-ranking pages.

    Using more factors for calculating Keyword Difficulty

    Many SEOs who use Ahrefs have been asking us to consider more factors when calculating our KD metric:

    Well, let’s say we decided to include Domain Rating (DR) in our calculation. Here’s what happens if we take two hypothetical keywords:

    • Keyword #1 – Has pages from DR 80+ websites ranking in the top 10, but none has any backlinks
    • Keyword #2 – Has pages from DR <40 websites in the top 10, but each of them has 40+ backlinks

    Which of these keywords should have a higher KD? And by how much?

    If you ask a few dozen SEOs to manually score these two keywords on a scale from 0 to 100, their estimates will be very different. That’s because each SEO professional will distribute the “weights” of DR and page-level backlinks differently when blending them into a single KD score.

    So by adding just one additional variable (DR), we’re causing a great deal of controversy to the calculation of KD and making it quite unintuitive.

    Hopefully, that explains why we decided to keep our KD metric super simple and only use the backlinks of the top-ranking pages to calculate it.

    This way, you know exactly what you’re looking at when applying a KD filter to your list of keywords. It gives you a straightforward benchmark of how many backlinks the top-ranking pages for each keyword have:

    • KD 0-5 – Top-ranking pages barely have any backlinks
    • KD ~50 – Top-ranking pages have a couple of hundred backlinks
    • KD 90+ – Top-ranking pages have thousands of backlinks

    But backlinks aren’t the only ranking factor. If you want to properly gauge your chances of ranking for a given keyword, you need to go further and do a more thorough analysis of the SERP.

    Speaking of which…

    Keyword difficulty as a concept

    Nobody knows exactly how Google ranks pages. But we do know the main things that matter for ranking well. And by analyzing those “main things,” SEOs can get a pretty good idea of what it takes to rank on Google for a given keyword.

    So here’s how they do it.

    1. Figure out how many backlinks you’ll need

    Backlinks act as votes, which tell Google that a given page is more valuable than any other page on the same topic. So, as a general rule, if you want to rank in the top 10 search results for a given keyword, you’ll have to acquire as many backlinks as the current top-ranking pages have (if not more).

    In Ahrefs’ Keywords Explorer, we actually have a text hint right under our KD score that tells you an approximate number of backlinks you’ll need:

    Keywords Explorer overview of "best backpack"; notably, there's a text hint below the KD score

    Two important caveats here:

    1. The hint says “to rank in the top 10,” which means that getting as many (or more) backlinks as your competitors won’t guarantee that you’ll rank #1. But there’s a very good chance that you’ll rank somewhere in the top 10.
    2. The sheer quantity of backlinks can often be misleading because some backlinks cast a stronger vote than others. So this number is merely an estimation.

    To properly estimate the strength of the backlink profiles of the top-ranking pages, you’ll have to review all their backlinks manually, i.e., do a backlink audit of these pages.

    In Keywords Explorer, we’ve created a handy shortcut for this, since each number in the “SERP Overview” links to its respective backlink report in Ahrefs’ Site Explorer:

    SERP overview for "best backpack"

    Click these numbers (in the highlighted columns) to manually review backlinks.

    2. Review the “authority” of your competitors

    Many SEOs believe that Google often gives preference to pages that belong to big, popular websites. So if there are lots of these on a SERP, they recommend you to stay away—unless your website is just as big and famous.

    And while we don’t necessarily agree with such an assessment, we do think it may be quite useful to peek at how authoritative the top-ranking websites are.

    Google itself has consistently denied that it uses any form of sitewide authority metric in its ranking algorithm. But I can think of at least two ways how a high website authority can indirectly contribute toward a higher ranking on Google:

    A. Internal links

    High DR means that a given website has lots of strong pages with high authority. And the page that you see ranking on Google may be receiving lots of “link juice” from such pages, making it a high-authority page too (even in the absence of backlinks from other websites).

    B. Familiar brand

    When presented with a list of search results, many people will prefer to click on the websites that are familiar to them. Google is allegedly tracking some “behavioral factors” to better understand if people were satisfied with the search results. And that can lead to “familiar websites” getting a ranking preference because that is what searchers want to get.

    3. Investigate the search intent

    Your ability to address the search intent is of utmost importance for ranking well on Google. In case you’re unfamiliar with the term, search intent is basically the expectation that searchers have. Google’s goal is to fulfill people’s expectations when they perform a search.

    Many marketers (including our own Joshua Hardwick) tend to group all searches into four distinct search intent buckets: informational, navigational, transactional, and commercial.

    But I’m not a big fan of that approach.

    Let me give an example. Instead of trying to figure out if the search query “backlink checker” is informational, navigational, or transactional (and what that means for your page anyway), it is much more productive to review the actual top-ranking pages for that keyword and analyze what searchers get from them.

    SERP overview for "backlink checker"

    As you can tell from the screenshot above, all the top-ranking pages for the keyword “backlink checker” are free online tools. So the search intent of this keyword is “a free online tool to check backlinks.”

    Thus, if you try to target this keyword with a blog article or a landing page, it won’t work.

    I know this for a fact because we actually tried it.

    Organic traffic for our "backlink checker" page increased after we nailed search intent

    Above is the graph of organic search traffic to our backlink checker page.

    Before the end of 2019, it was just a simple landing page explaining that Ahrefs has a backlink checker tool and offering people to sign up for our paid trial. No matter how much we optimized that page, it never ranked higher than #8 for that keyword.

    Then we studied the pages that were outranking us and realized that all of them were free online tools. And as soon as we converted our landing page into a free tool, it shot up to #1 for the keyword “backlink checker” and started ranking high for many other relevant keywords.

    Infographic showing the before (landing page) and after (page to use free tool) versions of our "backlink checker" page

    So instead of trying to decide if the search intent of your keyword is “transactional” or “informational,” just browse the top-ranking pages and figure out what exactly people expect to get from it.

    4. Gauge the quality of content

    The famous Skyscraper technique has led lots of content marketers astray by suggesting that a longer and more detailed article equals a better article.

    But just making your article longer doesn’t necessarily make it better. A better article is one that provides more value in less time (and without boring you to death).

    So here are some pointers that will help you gauge the quality of content that already ranks at the top for your target keyword:

    1. Does it provide accurate and up-to-date information?
    2. Is it written by a subject matter expert?
    3. Does it contain unique information?
    4. Is it well-written?
    5. Is it properly formatted?
    6. Is it well-designed?

    The first three are the most important ones. Google wants to provide its users with accurate information that comes from credible sources. We know that for a fact because the latest edition of its Search Quality Rater Guidelines has lots of focus on the concept called E-A-T, which stands for expertise, authoritativeness, and trustworthiness.

    So instead of making your pages longer than those of your competitors, try investing in E-A-T.

    What is a good Keyword Difficulty to target?

    As with many things in SEO, the answer is it depends:

    • On the authority of your website.
    • On your credibility in a given space.
    • On your ability to acquire backlinks.
    • On whether you have the ability and/or resources to cater to search intent.
    • Etc.

    A good exercise that may help you get used to Ahrefs’ KD metric is to look up the KD scores of the keywords that your website is already ranking for.

    You can do this by entering your website into Ahrefs’ Site Explorer and visiting the Organic keywords report:

    Organic keywords report for Ahrefs' blog showing KD scores of keywords

    This gives you a nice benchmark. But it’s by no means a substitute for the process I’ve outlined above. If you want to accurately estimate your chances of ranking for a given keyword, you should thoroughly study the top-ranking pages and factor in your own skills and resources.

    And please don’t shy away from targeting high-KD keywords. When it comes to many of the KD 70+ keywords that we rank for today, it took us four to five rewrites, lots of promotion, and many years of patience to get there. So the sooner you “attack” a high-KD keyword that you really want to rank for, the sooner you’ll get there.

    Final thoughts

    It would be quite awesome to have a keyword difficulty metric that could accurately predict your chances of ranking for a given keyword. But as you can probably tell by now, such a metric doesn’t exist.

    So the only way for you to make the right SEO bets is by thoroughly studying the search results for the keywords that you want to rank for.

    I hope the process I’ve outlined above is helpful for you. And if you have any further questions, feel free to ping me on Twitter.

    Article Performance
    Data from Ahrefs
    • Organic traffic
    • Linking websites

    The number of websites linking to this post.

    This post's estimated monthly organic search traffic.