Challenge Library
Coding Challenges
5,893 curated questions across every arena — browse by topic, then jump into a live 3-minute battle to put them to the test.
Filter by type
Filter by difficulty
Popular topics
20 challenges matching your filters
Clear topic filter- Multiple ChoiceIntermediate
[HTTP API] Allow-Origin Cross-Origin Resource Sharing
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Preflight Cross-Origin Resource Sharing
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Credentials Cross-Origin Resource Sharing
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Custom headers Cross-Origin Resource Sharing
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Max age Cross-Origin Resource Sharing
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Content-Type Request/response metadata
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Authorization Request/response metadata
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Cache-Control Request/response metadata
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Accept Request/response metadata
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] User-Agent Request/response metadata
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Single field Partial update of a resource
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] JSON Patch Partial update of a resource
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Non-idempotent Partial update of a resource
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Bandwidth Partial update of a resource
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Merge Patch Partial update of a resource
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Full replace Fully replace a resource
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Idempotent Fully replace a resource
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Upsert Fully replace a resource
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] vs PATCH Fully replace a resource
qahttphttpqa - Multiple ChoiceIntermediate
[HTTP API] Conditional Fully replace a resource
qahttphttpqa
Practice now, dominate the arena
Every challenge here is drawn from the live Code Royale pool. Review a question, then head to the arena to answer under pressure against a real opponent — 3-minute matches, Elo ranking, and badge tiers on the line.