Keyword difficulty
Keyword difficulty is an SEO tool's estimate of how hard it would be to rank on Google's first page for a search, usually on a scale of 0 to 100.
Keyword difficulty is a score from an SEO tool that estimates how hard it would be to get a page onto Google's first page for a search. Most tools show it from 0 to 100, where higher means harder.
It's useful for choosing your battles. A new site has a better chance with searches its competitors haven't sewn up, so difficulty helps you decide where to start.
How tools work it out
Each tool has its own formula, and their scores for the same search can differ a lot. Most lean heavily on the links pointing to the pages that already rank: if the top ten results all have links from hundreds of sites, the score is high. Some also weigh the strength of the ranking domains, or how many ads and other features crowd the results page.
Because it's an estimate, treat it as a guide. A score of 30 from one tool isn't comparable with a 30 from another, and none of them knows how good your page will be.
Reading it alongside volume
Difficulty is usually read next to search volume. For example, "coffee subscription" might be hard and searched a lot, while "decaf coffee subscription for two" is easy and searched a little. A new brand like Harrow & Pine may do better winning ten of the easy ones than chasing the hard one for a year.
Difficulty in AI search
There's no settled equivalent for AI answers yet. The nearest signal is how many brands the answers already name, and how firmly. A question where every answer names the same three big brands is a hard one. A question where answers name different brands every day, or none at all, is more open.