FastAPI vs Ruby on Rails
Security & risk comparison · Updated October 2026
How does FastAPI compare to Ruby on Rails on security, AI-readiness, and total cost of ownership? We scored both across 7 dimensions using NVD/NIST CVE data, GitHub metrics, and our census of the Tranco top 100,000.
FastAPI scores 82/100 overall versus Ruby on Rails's 64/100. FastAPI has 8 total CVEs compared to Ruby on Rails's 180, giving it a smaller vulnerability surface. (Source: WebPulse framework scoring, NIST NVD and CISA KEV, updated October 2026)
Who actually runs FastAPI and Ruby on Rails
Share of sites with an identified platform, from WebPulse's scan of the Tranco top 100,000 and our Common Crawl census.
| Where | FastAPI | Ruby on Rails |
|---|---|---|
| Top 1,000 | 0.0% (0) | 3.3% (7) |
| Top 10,000 | 0.1% (2) | 3.3% (85) |
| Top 100,000 | 0.0% (13) | 3.0% (832) |
| Wider web | 0.0% | 0.9% |
Highest-ranked sites on FastAPI
- dmm.com#4,545
- courtlistener.com#6,757
- cert.org#17,544
- pullkin.eu#18,881
- kik.com#19,550
Highest-ranked sites on Ruby on Rails
- www.gov.uk#308
- duolingo.com#457
- goodreads.com#463
- openstreetmap.org#579
- service.gov.uk#666
Detected from each homepage's HTML, headers and cookies in September 2026. Methodology
| Metric | FastAPI | Ruby on Rails |
|---|---|---|
| Total CVEs | 8 | 180 |
| Critical CVEs | 0 | 18 |
| Exploited (KEV) | 0 | 2 |
| CVEs last year | 2 | 15 |
| Avg CVSS | 3.5 | 5.8 |
| Security score | 90/100 | 62/100 |
FastAPI scores 83/100. Verdict: Recommended.
Ruby on Rails scores 65/100. Verdict: Acceptable.
Data sourced from NVD/NIST CVE database, GitHub API, and WebPulse framework scanner. Scores calculated using a 7-dimension model covering security, performance, ecosystem health, AI-readiness, developer experience, market trajectory, and cost of ownership. Updated October 2026.