Keyword difficulty is a score, usually on a 0 to 100 scale, that SEO tools assign to a keyword to estimate how hard it would be to rank on the first page for it. Google does not publish any such number. Each tool builds its own score from signals it can measure, most often the links pointing at the pages that currently rank, so the same keyword can get very different scores in different tools.
How tools calculate it
Most difficulty scores look at the pages currently ranking in the top results and measure how strong they appear. The most common input is backlink data: how many sites link to those pages and how strong those sites are. Some tools also factor in domain-level authority metrics, content signals or the presence of SERP features.
Because the formulas are proprietary and the underlying link indexes differ, one tool might call a keyword easy while another calls it hard. Compare scores within one tool, not across tools.
What the score leaves out
Difficulty scores are generic. They do not know your site, your existing rankings on related topics, or how well your page would answer the search. A site that already covers a subject in depth may rank for a keyword that scores as hard, while a new site may struggle with one that scores as easy.
They also tend to ignore intent mismatch. If the top results are all product pages and you plan a blog post, the real difficulty is higher than the score suggests, because Google has signaled it wants a different kind of page.
A better way to judge difficulty
Open the results page and look. Who ranks: large publishers, review sites, direct competitors, or small blogs? Do the ranking pages answer the search well, or are they thin and dated? Is there room for the kind of page you can make?
- The type of site that ranks, and whether yours is similar
- How closely the ranking pages match the search
- How recently they were updated
- Whether SERP features push organic results down
- Whether you already rank for related searches
Using difficulty in prioritization
Difficulty works best as one input alongside business value. A hard keyword with clear buying intent may be worth a long effort; an easy keyword with no connection to your product is rarely worth any. Many SaaS teams start with lower-difficulty, high-value searches, such as specific comparisons and use cases, to build relevance before going after broad terms.
Example
Two tools, two answers
A hypothetical analytics startup checks “product analytics for mobile apps” in two tools. One rates it 28 out of 100, the other 51. Neither number is wrong; they measure different things.
The team looks at the results page instead. The top results are long-standing vendor pages from well-known competitors, plus one review site. That tells them the search is winnable only with a strong, specific page and some patience, which is the decision the score was supposed to support.
Common mistakes
Comparing scores across tools
Each tool uses its own formula and link index. A 40 in one tool and a 40 in another do not mean the same thing.
Avoiding every hard keyword
Some of the most valuable searches for a SaaS company are competitive. Filtering them out by score alone can leave the plan full of easy searches nobody buys from.
Never looking at the actual results
The score is a summary. The results page shows who you are really up against and what kind of page Google prefers.
Questions
No. Keyword difficulty is a metric created by third-party SEO tools. Google Ads' Keyword Planner shows a “competition” level, but that refers to advertiser competition for ads, not organic ranking difficulty.
There is no universal threshold, since scales differ by tool and sites differ in strength. Compare candidates within one tool and check the results page before deciding.
