Keyword Difficulty (KD)
A 0-100 score estimating how hard it is to rank on Google's first page for a keyword.
Keyword difficulty is a tool's estimate, usually 0 to 100, of how hard it would be to rank for a term. Every vendor computes it differently, mostly from the link profiles of the current top results, so scores are not comparable between tools. Use it to rank candidates against each other, never as an absolute.
Definition
Keyword Difficulty is a metric (typically 0-100) that estimates how hard it would be to rank on page 1 of Google for a specific keyword. It factors in the authority, backlink profile, and content quality of currently ranking pages.
Different tools calculate KD differently — Ahrefs focuses on backlinks needed, Moz uses Page Authority, and Semrush uses a composite score. There is no universal standard.
Why It Matters
Targeting only high-KD keywords is a common mistake for new sites. A DR-10 site going after a KD-80 keyword is wasting time. Smart SEO targets low-KD long-tail keywords first, builds authority, then attacks harder terms.
Example
"SEO" has KD 95+ (nearly impossible for new sites). "SEO audit tool for small business" might have KD 25 — realistic to rank for within 3-6 months with quality content.
Related Terms
Know the term.
Check your own site.
A free audit tells you whether this is currently costing you score points — and exactly what to change.
Run a free audit