The Most Ignored Metric in SEO
Everyone looks at search volume.
Almost nobody properly evaluates keyword difficulty.
And then they wonder why they've been blogging for two years with zero rankings.
sighs deeply
What Keyword Difficulty (KD) Actually Measures
Most tools calculate KD based on the backlink profiles of the pages currently ranking on page one. Understanding what backlinks are and why they matter is essential context here.
Translation: how hard will it be to outrank the pages that already own this keyword?
A KD of 90 means the top results have monster backlink profiles. You're bringing a knife to a gunfight.
A KD of 15 means the door is wide open. Walk right in.
Why KD Scores Vary Across Tools
Ahrefs KD and Moz KD and SEMrush KD are NOT the same thing.
They use different formulas. Different data. Different scales.
A KD of 30 in Ahrefs might be a KD of 55 in SEMrush. SEMrush's own keyword research guide explains their methodology if you want the gory details.
Pick one tool. Stay consistent. Don't cross-reference KD scores between tools — it'll make your head spin.
The KD Rule We Use After 500+ Campaigns
New site (DA under 20): Target KD 0-20 only.
Growing site (DA 20-40): Target KD 0-35.
Established site (DA 40+): Go after KD 0-50, sprinkle in some 50-70.
Nobody should chase KD 80+ keywords until they've dominated the lower-difficulty ones first.
Come closer. Listen.
The sites that win don't start at the top. They build a base of easy wins, earn authority, then climb. We cover this approach in more detail in our SEO for startups guide.
KD Isn't Everything
A keyword with KD 10 and zero buyer intent is still useless.
A keyword with KD 40 that drives $50,000/month in revenue is worth the fight.
Always pair KD with intent and business value.
Start With a System
Our 113-task checklist at SEO Checkup includes keyword evaluation steps so you never waste months chasing unwinnable keywords.
Free. No credit card. 30 seconds.