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
Multi-column
frontendintermediate - Multiple ChoiceHard
content-visibility
frontendhard - Multiple ChoiceHard
subgrid
frontendhard - Multiple ChoiceIntermediate
Grid auto-flow
frontendintermediate - Multiple ChoiceHard
ARIA Live Regions
frontendmcqhard - Multiple ChoiceHard
Content Security Policy
frontendmcqhard - Multiple ChoiceIntermediate
Grid fr Unit
frontendmcqintermediate - Multiple ChoiceIntermediate
Specificity
frontendmcqintermediate - Multiple ChoiceIntermediate
Event Delegation
frontendmcqintermediate - Multiple ChoiceBeginner
flex-grow
frontendmcqbeginner - Multiple ChoiceIntermediate
Input Events
frontendmcqintermediate - Multiple ChoiceHard
Layout Thrashing
frontendmcqhard - Multiple ChoiceIntermediate
Passive Listeners
frontendmcqintermediate - Multiple ChoiceBeginner
Responsive Images
frontendmcqbeginner - Multiple ChoiceIntermediate
Core Web Vitals
frontendintermediate - Multiple ChoiceIntermediate
Lazy loading
frontendintermediate - Multiple ChoiceIntermediate
Code splitting
frontendintermediate - Multiple ChoiceIntermediate
Tree shaking — Module Bundlers
frontendintermediate - Multiple ChoiceIntermediate
Image optimization
frontendintermediate - Multiple ChoiceIntermediate
Caching strategies
frontendintermediate - Multiple ChoiceHard
Critical CSS
frontendhard - Multiple ChoiceIntermediate
Font optimization
frontendintermediate - Multiple ChoiceIntermediate
Bundle analysis
frontendintermediate - Multiple ChoiceIntermediate
Preload/prefetch
frontendintermediate - Multiple ChoiceIntermediate
Debouncing
frontendintermediate - Multiple ChoiceIntermediate
Throttling
frontendintermediate - Multiple ChoiceHard
Virtual scrolling
frontendhard - Multiple ChoiceHard
Memory leaks
frontendhard - Multiple ChoiceHard
Web Vitals TBT
frontendhard - Multiple ChoiceIntermediate
Compression
frontendintermediate - Multiple ChoiceIntermediate
HTTP/2 multiplexing
frontendintermediate - Multiple ChoiceIntermediate
3rd-party impact
frontendintermediate - Multiple ChoiceHard
Layout thrashing
frontendhard - Multiple ChoiceIntermediate
Performance budget
frontendintermediate - Multiple ChoiceHard
PRPL pattern
frontendhard - Multiple ChoiceIntermediate
Service Workers
frontendintermediate - Multiple ChoiceIntermediate
Web App Manifest
frontendintermediate - Multiple ChoiceHard
Cache API
frontendhard - Multiple ChoiceHard
Push notifications
frontendhard - Multiple ChoiceHard
Background Sync
frontendhard - Multiple ChoiceIntermediate
Offline-first
frontendintermediate - Multiple ChoiceIntermediate
Web Share API
frontendintermediate - Multiple ChoiceHard
Payment Request API
frontendhard - Multiple ChoiceHard
Credential Management
frontendhard - Multiple ChoiceHard
WebRTC
frontendhard - Multiple ChoiceIntermediate
Screen Wake Lock
frontendintermediate - Multiple ChoiceIntermediate
Device Orientation
frontendintermediate - Multiple ChoiceIntermediate
Battery Status
frontendintermediate - Multiple ChoiceIntermediate
Network Information
frontendintermediate - Multiple ChoiceHard
Web Bluetooth
frontendhard - Multiple ChoiceIntermediate
PWA install prompt
frontendintermediate - Multiple ChoiceHard
Workbox
frontendhard - Multiple ChoiceHard
Web Vitals in PWA
frontendhard - Multiple ChoiceBeginner
Media queries — Breakpoints
frontendbeginner - Multiple ChoiceIntermediate
Mobile-first — Progressive Enhancement
frontendintermediate - Multiple ChoiceIntermediate
Fluid typography
frontendintermediate - Multiple ChoiceIntermediate
Responsive images
frontendintermediate - Multiple ChoiceIntermediate
Viewport units
frontendintermediate - Multiple ChoiceIntermediate
Breakpoints
frontendintermediate - Multiple ChoiceHard
Container queries (128)
frontendhard
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.