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.
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4,318 challenges matching your filters
- Multiple ChoiceIntermediate
History API
frontendintermediate - Multiple ChoiceIntermediate
Geolocation API
frontendintermediate - Multiple ChoiceIntermediate
Notification API
frontendintermediate - Multiple ChoiceIntermediate
Web Workers
frontendintermediate - Multiple ChoiceIntermediate
requestAnimationFrame
frontendintermediate - Multiple ChoiceIntermediate
Canvas API
frontendintermediate - Multiple ChoiceIntermediate
WebSocket API
frontendintermediate - Multiple ChoiceHard
IndexedDB
frontendhard - Multiple ChoiceIntermediate
File API
frontendintermediate - Multiple ChoiceIntermediate
Clipboard API
frontendintermediate - Multiple ChoiceIntermediate
Fullscreen API
frontendintermediate - Multiple ChoiceIntermediate
Page Visibility
frontendintermediate - Multiple ChoiceBeginner
console API
frontendbeginner - Multiple ChoiceIntermediate
Performance API
frontendintermediate - Multiple ChoiceHard
ResizeObserver
frontendhard - Multiple ChoiceIntermediate
URL API
frontendintermediate - Multiple ChoiceHard
Broadcast Channel
frontendhard - Multiple ChoiceIntermediate
Crypto API
frontendintermediate - Multiple ChoiceIntermediate
BEM
frontendintermediate - Multiple ChoiceIntermediate
CSS Modules
frontendintermediate - Multiple ChoiceIntermediate
Tailwind CSS
frontendintermediate - Multiple ChoiceIntermediate
CSS-in-JS
frontendintermediate - Multiple ChoiceIntermediate
Sass/SCSS
frontendintermediate - Multiple ChoiceIntermediate
PostCSS
frontendintermediate - Multiple ChoiceIntermediate
CSS custom properties
frontendintermediate - Multiple ChoiceHard
ITCSS
frontendhard - Multiple ChoiceHard
OOCSS
frontendhard - Multiple ChoiceHard
SMACSS
frontendhard - Multiple ChoiceIntermediate
Design tokens
frontendintermediate - Multiple ChoiceBeginner
CSS reset
frontendbeginner - Multiple ChoiceIntermediate
Utility classes
frontendintermediate - Multiple ChoiceIntermediate
Component-driven
frontendintermediate - Multiple ChoiceHard
Critical CSS extraction
frontendhard - Multiple ChoiceIntermediate
webpack
frontendintermediate - Multiple ChoiceIntermediate
Vite
frontendintermediate - Multiple ChoiceIntermediate
Babel
frontendintermediate - Multiple ChoiceIntermediate
ESLint
frontendintermediate - Multiple ChoiceBeginner
Prettier
frontendbeginner - Multiple ChoiceIntermediate
Source maps
frontendintermediate - Multiple ChoiceIntermediate
HMR
frontendintermediate - Multiple ChoiceIntermediate
Environment variables
frontendintermediate - Multiple ChoiceBeginner
npm scripts
frontendbeginner - Multiple ChoiceIntermediate
TypeScript
frontendintermediate - Multiple ChoiceIntermediate
Tree shaking
frontendintermediate - Multiple ChoiceIntermediate
Asset hashing
frontendintermediate - Multiple ChoiceBeginner
Minification
frontendbeginner - Multiple ChoiceIntermediate
Bundle splitting
frontendintermediate - Multiple ChoiceIntermediate
CI/CD for frontend
frontendintermediate - Multiple ChoiceHard
Compound components
frontendhard - Multiple ChoiceIntermediate
Render props
frontendintermediate - Multiple ChoiceIntermediate
Higher-Order Components
frontendintermediate - Multiple ChoiceIntermediate
Custom hooks
frontendintermediate - Multiple ChoiceIntermediate
Controlled vs uncontrolled
frontendintermediate - Multiple ChoiceIntermediate
Portal
frontendintermediate - Multiple ChoiceIntermediate
Error boundaries
frontendintermediate - Multiple ChoiceIntermediate
Suspense
frontendintermediate - Multiple ChoiceIntermediate
Composition
frontendintermediate - Multiple ChoiceIntermediate
Slots
frontendintermediate - Multiple ChoiceIntermediate
Presentational/Container
frontendintermediate - Multiple ChoiceIntermediate
Provider pattern
frontendintermediate
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.