KDP Category Opportunity Scanner
Scan 88 Kindle Store best-seller categories for competition vacancy — median review counts, weak-competitor share of the top 20, and breakout books that prove newcomers still crack the top 15. Free, no sign-up.
Top categories by vacancy score (static summary — full interactive ranking below)
| # | Category | Score | Median reviews |
|---|---|---|---|
| 1 | Computers & Technology | 62.0 | 199 |
| 2 | Databases | 52.0 | 91.5 |
| 3 | Programming | 50.5 | 224 |
| 4 | Taxation | 49.5 | 160.5 |
| 5 | Networking & Communications | 48.5 | 127 |
| 6 | Industries | 47.0 | 937.5 |
| 7 | Job Hunting & Careers | 45.5 | 677.5 |
| 8 | Real Estate | 45.5 | 300.5 |
| 9 | Women & Business | 45.5 | 341.5 |
| 10 | Biographies | 45.0 | 1,318.5 |
| 11 | Security & Encryption | 45.0 | 185.5 |
| 12 | Arctic & Antarctica | 44.5 | 165 |
| 13 | Business | 44.5 | 451.5 |
| 14 | Organizational Behavior | 44.5 | 2,723 |
| 15 | Biography & History | 43.5 | 2,483 |
How to read the quadrants
- Low competition
- Median review count under 30 and at least half of the top 20 has fewer than 100 reviews — incumbents are weak, but verify demand exists.
- Opportunity
- Healthy demand (median ≥100 reviews) with at least a quarter of the top 20 still under 100 reviews.
- Fortress
- Fewer than 15% of the top 20 are weak competitors and the median exceeds 500 reviews — established authors hold the list.
- Middle
- Between the other quadrants — read the score and breakout books before judging.
Research snapshot of 88 Kindle Store best-seller categories, scanned between Oct 2026 and Oct 2026. Refreshed periodically — not live tracking.
Validate your niche before you write
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