Everything you need to know

Keyword difficulty isn’t one of SEO’s hottest topics or latest trends. But it is a powerful metric when you understand its potential.

It can help you to make educated decisions about your prospects of ranking for specific terms, allowing you to make tactical choices that underpin your SEO strategy.

Here’s what keyword difficulty means for SEO, how the score is measured and tips for using it to get better results.

What is keyword difficulty?

Keyword difficulty is a metric that quantifies how competitive a keyword is and, therefore, how challenging it’s likely to be to rank for it. It is displayed as a value from 1 (low competition) to 100 (extremely high competition).

What does the score tell you?

Keyword difficulty in SEO tells you how difficult it’s likely to be to rank for a particular keyword in relation to the strength of the competition. However, there’s no standard for calculating the difficulty or competition to rank for a particular keyword. 

Various tools measure it differently, and scores can vary significantly based on which one you use. 

If you’re interested in this, it’s worth checking out Backlinko’s research into keyword difficulty scores across different SEO tools

Most tools factor the strength and number of referring domains pointing to the top ranking results in the search engines into their calculation, but many use additional metrics too. 

Where do you find it?

There are a variety of different SEO tools that provide a keyword difficulty checker. 

It is usually found in the keyword research function of a tool and displayed alongside the search volume metric, labeled difficulty, competition or KD

To check the competition for keywords at scale, you will likely need a paid keyword research tool. Here are some of the most well-known:


Navigate to Keywords Explorer and you can begin your search. The difficulty score is clearly labeled and color-coded along with descriptive text to help you understand the difficulty level. 

How is it calculated?

Ahrefs CMO Tim Soulo explains in detail: 

“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.”


In the Keyword Overview section of Semrush, you’ll find their difficulty metrics. There’s also a KD column in keyword reports. 

Semrush - Keyword difficulty

How is it calculated?

Semrush uses SERP analysis, keyword analysis and a score weighting based on locality. You can read the full details here


The keyword explorer in Moz gives you an immediate score that’s easy to find and interpret. 

Moz - Keyword difficulty

How is it calculated?

In their help section, Moz explains: 

“Keyword Difficulty in Keyword Explorer takes into account the Page Authority (PA) and Domain Authority (DA) scores of the results ranking on the first page of Google for the given query, as well as modifying intelligently for projected

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