Prague is about 35 times bigger than Cocos (Keeling) Islands.

Cocos (Keeling) Islands is approximately 14 sq km, while Prague is approximately 496 sq km, making Prague 3,444% larger than Cocos (Keeling) Islands.
Tip: This to-scale comparison of Cocos (Keeling) Islands vs. Prague uses the Mercator projection, which distorts the size of regions near the poles.