·3 min
Keyword Difficulty
SEOkeyword research
What is keyword difficulty?
Keyword difficulty (KD) is a metric that indicates how hard it is to rank in Google's TOP 10 for a given keyword. Most SEO tools (Ahrefs, Semrush, Moz) calculate KD on a 0-100 scale, primarily based on the backlink profile of pages currently ranking for that keyword.
KD 0-20 = easy, 20-50 = medium, 50-70 = hard, 70+ = very hard.
Why does it matter?
- Prioritization — allows you to focus on keywords where you have a realistic chance
- Resource estimation — high KD = more content and links needed
- Strategy — new domains should start with KD 0-30 keywords, not KD 70+
How do tools calculate KD?
| Tool | Primary factor | Scale |
|---|---|---|
| Ahrefs | Referring domains of pages in the TOP 10 | 0-100 |
| Semrush | Backlinks + authority + traffic | 0-100 (%) |
| Moz | Domain Authority of pages in the TOP 10 | 0-100 |
Each tool calculates KD differently — do not compare values across tools.
Pick one tool and stay with it, so that your KD thresholds mean the same thing from one month to the next. If you have not chosen yet, see Ahrefs or Semrush for how the two differ beyond this metric.
What else affects real difficulty?
KD from tools is a simplification. Real difficulty also depends on:
- Topical authority — if you have authority in a niche, you rank more easily even on keywords with high KD
- Search intent — does your page match the intent? If the TOP 10 consists of comparisons and you have a blog post, KD is effectively higher
- Quality of content in the TOP 10 — if current results are weak, it is easier to outperform them
- SERP features — featured snippets and AI Overviews steal clicks
Keyword selection strategy
- New domain (DR < 20) — target KD 0-20, long-tail keywords
- Growing domain (DR 20-40) — KD 10-40, build content clusters
- Strong domain (DR 40+) — you can target KD 30-60
- Always verify manually — check the TOP 10 for a given keyword and assess whether you have a chance
Related Terms
- Keyword research — the process of researching keywords
- Long-tail keyword — long-tail keywords
- Domain Rating — domain strength metric
- SERP — search engine results page