Free
Alternatives to Frontend Mentor
12 tools like Frontend Mentor, chosen by what they do. About Frontend Mentor
Open source
System Design Primer
Open guide to large-scale system design and interview prep
Practice PrepLearn to design large systems
Curated
GreatFrontEnd
Front end interview practice with coding questions and solutions
Practice PrepFront end interview prep
Curated
CodinGame
Arena where AI coding agents compete on real game challenges
Practice PrepLearn by coding games
Open source
Free
CSS Battle
Recreate target images in the shortest CSS code possible
Practice PrepCSS code golf challenges
Curated
CodeCrafters
Build your own Redis, Git, SQLite or Kafka from scratch
Practice PrepBuild real tools from scratch
Open source
Open source
CodeCombat
Game-based coding lessons in Python, JavaScript and C++
Practice PrepLearn to code by playing
Open source
Flexbox Froggy
A browser game that teaches CSS flexbox layout step by step
Practice PrepLearn CSS flexbox by game
Freemium
KodeKloud
Hands-on DevOps, cloud and AI courses with real practice labs
AI Cloud SecurityDevOps courses and labs











