The Keyword Difficulty is a metric that, on 3 levels (easy, medium, hard), estimates the effort it would take for a specific website to rank in the top 10 positions for a keyword.

How does this work?

First off, the Difficulty is calculated/updated whenever a keyword:

  • is added to the rank tracker,

  • enters or exits the top 10,

  • enters or exits the top 100, or

  • has a rank change of more than 30%.

We use 2 keyword database sources to extract the necessary data for the estimation:

  • our own keyword databasess – for the UK, the US & RO markets.

  • SERPstat’s keyword databases, for the rest of the world.

There are 2 algorithms for estimating this keyword difficulty based on ranking:

  1. Keywords ranking in the Top 100.

  2. Keywords ranking outside the Top 100.

1. The Difficulty algorithm for keywords ranking in the Top 100

The core metric used for calculating the difficulty metric is the Topical Authority:

Topical Authority = estimated monthly organic traffic a page would get, based on keyword rankings and search volumes.

It is calculated for each of the 100 ranking landing pages in the keyword’s SERP and then the following key variables are computed:

1.1. The difference in Page Authority (Delta Page Authority)

The difference between your landing page’s Authority and the Authority of the landing pages in the Top 10.

[Delta Page Authority] = [Your page Authority] / [Avg. Top 10 Authority]

The output is simplified into 3 values in terms of difficulty:

  • HIGH: [Delta Page Authority] < 0.1

  • MEDIUM: [Delta Page Authority] >= 0.1 and <= 0.5

  • LOW: [Delta Page Authority] > 0.5

1.2. The Distance until the Top 10

This looks at how many landing pages with a higher Authority are in front of you, but up until the top 10 (so including position 11).

These are pages with the same Content Focus, but a higher Authority.

The process for calculating the distance:

  • We calculate the Authority for all ranking pages, from your current rank and up to rank #11

  • The keyword is then split into individual words (longer than 3 characters).

  • We then search for these in the Title of your page and of all the pages that have a higher Authority than yours, and we output [No/Partial/Full Match] as a parameter.

  • Finally, depending on the keyword match within your page title, the algorithm counts the higher authority pages in front of you, as follows:

    • No match → only counts the pages that have “No match” in the title

    • Partial match → counts the pages with “No match” / “Partial match” in the title

    • Full match → counts all pages

The final output is simplified into 3 values (of difficulty), depending on the number of more authoritative pages ahead of your page:

  • LOW: [# Higher Authoritative Pages] <= 10

  • MEDIUM: [# Higher Authoritative Pages] < 50 and > 11

  • HIGH: [# Higher Authoritative Pages] >= 50

1.3. Free slots in Top 10

This is simply the number of positions in the top 10 where there are NO big global players, like Youtube, Facebook, Wikipedia, Amazon, Google, LinkedIn.

[FREE SLOTS] = the number of positions in the top 10 where
there are no "big sites" that would keep their ranks within the top 10.

The output is also simplified into 3 values in terms of difficulty.

  • HIGH: [Free Slots] <= 3

  • MEDIUM: [Free Slots] >3 and <=7

  • LOW: [Free Slots] > 7

The final calculation

Combinations of the difficulty levels on each of the 3 metrics then give us the EASY/MEDIUM/HARD Keyword Difficulty.

2. The Difficulty algorithm for keywords ranking outside of Top 100

On the US/UK/RO markets

Starting with our keyword databases, we store all the ranking landing pages, which are all the pages with Topical Authority > 0.

To estimate the keyword difficulty for a website not yet ranking in the top 100, we look at how many pages target the keyword in their Title, partially or fully.

We split the keyword into separate words (longer than 3 characters) and search for it in the Title of the page, in all its forms (singular, plural, verb, etc). We’ll further refer to these as [Other pages with partial match].

We also analyze your best-ranking* page’s keyword-title match, with the same process. We’ll further refer to it as [Keyword in your page’s title]. It can take 3 values: No/Partial/Full Match.

*Note: The best-ranking page is automatically detected by SEOmonitor through a keyword search in Google with the site:[your-website] operator, searching for the keyword within your website’s pages. This is done automatically (whenever a keyword is not yet in Top 100).

Combinations of whether the keyword is in your page’s title and how many other pages have a partial match then give us the levels as EASY/MEDIUM/HARD keyword difficulty.

What does the Difficulty explanation look like?

  1. Keywords where your website ranks outside the Top 100:

    1. [X] authoritative landing pages with a full match of the keyword in the title.

    2. [Other Pages with Partial Match] authoritative landing pages with a partial match of the keyword in the title.

  2. Keywords where your website ranks within the Top 100:


  • (Quickly) finding out low-hanging fruit in any list of tracked keywords.

  • Build a good keyword strategy by avoiding keywords that are too difficult to pursue (for the time being).

  • Showing clients why you chose to focus on some keywords and not on others, to then create transparency and credibility with them.

  • And showing clients how these choices make your predictions more realistic.

Other notes

  • It's not a generic Keyword Difficulty, but the Difficulty to rank in top 10. Further within the top, it could be too sophisticated for the SEO needs. If your site is ranking within the top, you're already optimizing. So a top 10 metric is good enough, while also keeping the result relevant.

  • Because the Difficulty is relative to the ranking landing page, the same keyword tracked in multiple campaigns could have different Difficulty values.

  • And when the ranking improves, the difficulty gets easier and easier, until the page reaches the Top 10.

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