The difference between maxmind geoip and cloudflare geoip: country code level

Cloudflare provide free CF-IPCountry header, but we found a tweet said cloudflare's accuracy is not good enough at 2014.

We logged ip and cloudflare country code, then made a simple script to check the difference.

Dates of Cloudflare country code: first half of October, 2016

Maxmind geoip 2 country database: Oct 11, 2016

IPV4

All IPs: 560079

• cloudflare missed: 423
• maxmind missed: 27
• both missed: 667
• diff: 367
• matched: 558595

matched / all = 99.735%

If we used both database: 

(cloudflare missed + maxmind missed + matched) / all = 99.8154%

IPV6

All IPs: 41456

• cloudflare missed: 5
• maxmind missed: 0
• both missed: 0
• diff: 58
• matched: 41393

matched / all = 99.848%

If we used both database to complement country code: 

(cloudflare missed + maxmind missed + matched) / all = 99.8601%

Cloudflare didn't cllaimed the accuracy, but official Maxmind claimed accuracy is 99.8%.