Challenge Library
Coding Challenges
5,893 curated questions across every arena — browse by topic, then jump into a live 2-minute battle to put them to the test.
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5,893 challenges total
- Multiple ChoiceIntermediate
Flexbox wrapping
frontendintermediate - Multiple ChoiceIntermediate
Grid auto-fit
frontendintermediate - Multiple ChoiceIntermediate
Responsive tables
frontendintermediate - Multiple ChoiceIntermediate
Picture element — Art Direction
frontendintermediate - Multiple ChoiceHard
min/max functions
frontendhard - Multiple ChoiceHard
Device pixel ratio
frontendhard - Multiple ChoiceIntermediate
Orientation
frontendintermediate - Multiple ChoiceIntermediate
Hover/pointer
frontendintermediate - Multiple ChoiceIntermediate
Responsive embeds
frontendintermediate - Multiple ChoiceIntermediate
Testing responsiveness
frontendintermediate - Multiple ChoiceHard
Intrinsic design
frontendhard - Multiple ChoiceIntermediate
React Router
frontendintermediate - Multiple ChoiceIntermediate
Next.js routing
frontendintermediate - Multiple ChoiceIntermediate
SPA vs MPA
frontendintermediate - Multiple ChoiceIntermediate
Hash vs History
frontendintermediate - Multiple ChoiceIntermediate
Dynamic routes
frontendintermediate - Multiple ChoiceIntermediate
Nested routes
frontendintermediate - Multiple ChoiceIntermediate
Route guards
frontendintermediate - Multiple ChoiceIntermediate
Lazy loading routes
frontendintermediate - Multiple ChoiceIntermediate
404 handling
frontendintermediate - Multiple ChoiceIntermediate
Navigation guards
frontendintermediate - Multiple ChoiceIntermediate
Query params
frontendintermediate - Multiple ChoiceIntermediate
Scroll restoration
frontendintermediate - Multiple ChoiceIntermediate
Link prefetching
frontendintermediate - Multiple ChoiceIntermediate
Breadcrumbs
frontendintermediate - Multiple ChoiceHard
SSR routing
frontendhard - Multiple ChoiceBeginner
useState
frontendbeginner - Multiple ChoiceIntermediate
useReducer
frontendintermediate - Multiple ChoiceIntermediate
Context API
frontendintermediate - Multiple ChoiceIntermediate
Redux
frontendintermediate - Multiple ChoiceIntermediate
Zustand
frontendintermediate - Multiple ChoiceHard
Signals
frontendhard - Multiple ChoiceHard
Jotai/Recoil
frontendhard - Multiple ChoiceIntermediate
MobX
frontendintermediate - Multiple ChoiceHard
XState
frontendhard - Multiple ChoiceIntermediate
TanStack Query
frontendintermediate - Multiple ChoiceIntermediate
URL state
frontendintermediate - Multiple ChoiceIntermediate
Lifting state up
frontendintermediate - Multiple ChoiceIntermediate
Immutable updates
frontendintermediate - Multiple ChoiceHard
Optimistic updates
frontendhard - Multiple ChoiceHard
State normalization
frontendhard - Multiple ChoiceIntermediate
Jest
frontendintermediate - Multiple ChoiceIntermediate
React Testing Library
frontendintermediate - Multiple ChoiceIntermediate
Cypress
frontendintermediate - Multiple ChoiceIntermediate
Unit tests
frontendintermediate - Multiple ChoiceIntermediate
Integration tests
frontendintermediate - Multiple ChoiceIntermediate
E2E tests
frontendintermediate - Multiple ChoiceIntermediate
Mocking
frontendintermediate - Multiple ChoiceIntermediate
Snapshot testing
frontendintermediate - Multiple ChoiceIntermediate
Test coverage
frontendintermediate - Multiple ChoiceIntermediate
Accessibility testing
frontendintermediate - Multiple ChoiceHard
Visual regression
frontendhard - Multiple ChoiceHard
MSW
frontendhard - Code AnalysisHard
Trace: CORS Misconfig
fullstackanalysishard - Code AnalysisIntermediate
Trace: IDOR
fullstackanalysisintermediate - Code AnalysisHard
Trace: Token Storage
fullstackanalysishard - Code AnalysisIntermediate
Trace: API Fan-out
fullstackanalysisintermediate - Code AnalysisHard
Trace: Secret Leak in Bundle
fullstackanalysishard - Code AnalysisIntermediate
Trace: Stale UI After Mutation
fullstackanalysisintermediate - Multiple ChoiceIntermediate
RESTful principles
fullstackintermediate
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 — 2-minute matches, Elo ranking, and badge tiers on the line.