Understanding Keyword Difficulty

What keyword difficulty scores actually measure and when to trust or ignore KD metrics.

What Keyword Difficulty Scores Actually Measure

Tools like Ahrefs, Semrush, and Moz assign each keyword a difficulty score, usually ranging from 0-100. These scores are estimates of how hard it is to rank for a keyword. Sounds useful, right? But you need to understand what these scores actually measure—and what they do not.

Keyword difficulty scores primarily measure link competition. They look at the backlinks pointing to pages ranking in the top ten for a keyword, average them, and estimate how difficult it would be for a new site to build enough links to compete. This is useful information, but it is incomplete.

What KD scores do not measure: content quality competition, page topicality, on-page optimisation gaps, or how outdated or weak the top-ranking content actually is. A keyword with a KD of 50 might have weak top-ranking pages that have not been updated in three years. You could rank with a newer, better article and no link-building campaign at all. The KD score would not reflect that opportunity.

The KD Score Limitation

Keyword difficulty scores are a rough proxy for link competition. They should inform your decision, but not make it. Always manually assess the actual difficulty of the top ten results.

Manual Difficulty Assessment: Looking at What Actually Ranks

Search your target keyword and study the page one results. This is the real difficulty assessment.

Who is ranking? Are they domain-authority powerhouses (sites like Wikipedia, Forbes, government sites, major publications) or are there smaller, more niche sites mixed in? A keyword where position one is held by Wikipedia and position two by a major publication is legitimately difficult. A keyword where positions 3-10 are held by small blogs and niche sites might be easier than the KD score suggests.

How are the pages optimised? Do they have comprehensive, 5,000-word guides or are they shorter, thinner pages? Are the top ranking pages recent (updated in the last year) or are some of them 3-5 years old without updates? Do the pages have clear expertise signals (author bios, credentials, topical authority indicators) or do they feel like low-effort content?

A keyword where the top ten pages are all 500-word thin posts from small sites is easier than a keyword where position one is a 8,000-word comprehensive guide from an established authority site. You can assess this manually in minutes.

The SERP Stability Test

A useful manual test: search the same keyword from different accounts, devices, and locations. Does the search result stay consistent? Or does Google show different results?

Highly volatile SERP results (different pages rank one moment, different ones the next) often indicate an immature ranking landscape—fewer high-quality results competing, more room for a new page to gain traction. Stable, unchanging results often indicate a mature ranking landscape where the ranking signals are well-established and the top results are legitimately strong.

You can test this with different search accounts (incognito mode, different browsers, logged-in as different users) or by using a tool like SEMrush's SERP tracking feature that compares results over time.

Finding Your Sweet Spot: The Gap

Ideal keywords to target have: high search volume (or reliable consistent volume), moderate to high relevance to your business, moderate keyword difficulty (not zero difficulty, not near-impossible), and search intent that aligns with what you offer.

In practice, you are looking for gaps. Keywords where:

Volume is real (200+ monthly searches) but not saturated competition
The top ten results have some weak pages, not all powerhouse domains
You can create content that is demonstrably better than what currently ranks
Ranking for it would meaningfully contribute to your business goals

These gaps exist in nearly every niche. A KD score of 30-60 is typically the sweet spot for new or smaller sites. Not so hard that you need a massive link-building campaign, not so easy that there is no real opportunity.

New Domain vs Established Domain Strategy

If you are a brand new domain with no authority history, you should bias toward lower-difficulty keywords. That does not mean targeting no-volume keywords or keywords with zero intent match. It means if you have the choice between a KD-40 keyword and a KD-60 keyword, and both are relevant, start with the 40.

New domains can rank for high-difficulty keywords—but only if the on-page content is exceptional and you earn real links to the page. For most sites, that means building authority in lower-difficulty areas first, then expanding upward as your domain gains trust and citation metrics improve.

Established domains with strong backlink profiles can target higher-difficulty keywords more aggressively. A page on an established, authoritative site might rank for a KD-70 keyword after only moderate link building. The same keyword would be out of reach for a brand new site without a significant link campaign.

The Authority Multiplier

Domain authority multiplies your ability to rank for difficult keywords. This is why the order matters: start with moderate-difficulty keywords, build authority and links, then expand into higher-difficulty terms. Reversing this order wastes enormous effort.

How This Connects

You now understand both intent and difficulty. The combination of the two determines which keywords are actually worth pursuing. The next step is recognising that long-tail keywords—more specific, lower-volume keywords—often have better opportunity-to-difficulty ratios than broad terms. That is the focus of the next section.