Keyword Difficulty: What the Score Means and How to Check It Yourself

Put the same keyword into three SEO tools and you can get three different difficulty scores. One says 12, another says 34, a third labels it "possible". None of them is lying. They are measuring slightly different things, and none of them knows your site.

Keyword difficulty (KD) is a shortcut. It helps you sort a list of 500 keywords quickly. It should not be the final word on whether you write a page.

What keyword difficulty scores measure

Each tool has its own formula, and most don't publish every detail. In general, KD scores lean heavily on the backlink profiles of the pages currently ranking on page one: how many referring domains they have and how strong those domains are.

Ahrefs, for example, describes its KD as an estimate of how many referring domains you would need to reach the top ten. Other tools blend in factors like domain authority metrics and SERP features.

What KD scores usually don't account for well:

• How closely the ranking pages match search intent
• Content quality and freshness
• Your own site's existing authority on the topic
• Local or personalised results
• Whether a big site is ranking with a weak, off-topic page

That is why a "hard" keyword sometimes turns out to be easy, and an "easy" one stays out of reach.

Why scores differ between tools

Each tool runs its own crawler, so the link counts are different. Each uses a different scale and weighting. Some calculate from the top ten, some from the top twenty. Comparing a score from one tool to another tool's score is meaningless. Pick one tool and compare keywords against each other inside it.

The manual check that matters more

When a keyword looks promising, search it yourself (in an incognito window, set to your target country) and look at the first page. Ask five questions:

1. Do the ranking pages match the intent I plan to serve? If Google shows product pages and you want to write a guide, difficulty is effectively very high for you.
2. Who is ranking? National brands and government sites are hard to move. Forums, small blogs and thin affiliate pages are beatable.
3. How good is the content? Open the top three. If they are outdated, vague or badly structured, there is room.
4. Do the top pages have many links? Check the page-level referring domains in your tool, and compare against your own site's strongest pages. Our guide to reading a backlink report helps here.
5. What SERP features take up space? A map pack, shopping carousel, videos and an AI summary can push the first organic result well down the screen.

If three or more answers favour you, the keyword is worth a try regardless of the tool's number.

Your site changes the difficulty

A keyword is not equally hard for everyone. A cooking blog with 200 recipes and decent links will rank for a new recipe term faster than a brand-new site with the same article.

Two things change your personal difficulty:

• Topical relevance. If you have already covered the surrounding topic well, Google has more reason to trust a new page on it. See content clusters and pillar pages.
• Site authority and links. A site with an established link profile can compete on terms a new site cannot yet touch.

A rough way to calibrate: look at keywords you already rank for in the top ten and note their KD in your tool. That tells you the range your site can currently handle. Aim slightly above it, not far above.

A simple way to use KD in practice

For a newer site, a workable approach looks like this:

• Filter your list to low KD in your chosen tool.
• Remove anything where intent doesn't match what you can publish.
• Run the manual check on what remains.
• Sort by business value, not volume.

For an established site, include medium-difficulty terms where you already have topical depth, and plan to support those pages with internal links and some external links.

What to do with high-difficulty keywords

Don't delete them. Note them as long-term targets. Then build toward them with supporting content on narrower, related topics that link to a strong main page. A SaaS invoicing tool might not rank for "invoice software" in year one, but it can rank for "GST invoice format for freelancers" and "how to add HSN code to invoice", and those pages build the base for the bigger term.

High-difficulty terms usually also need links. Whatever approach you take to building them, keep the profile natural: varied sources, varied anchors and a steady pace rather than a sudden spike. The anchor text explainer covers the anchor side.

Start with this

Export the keywords you currently rank top ten for, note their difficulty scores in your main tool, and find your ceiling. Then pick five new keywords just above that ceiling, run the five-question manual check on each, and write for the two that pass.