Comparing the Best React Challenge Platforms in 2025

Platform	Price	Tests	React Challenges	Other Challenges	Technology	Editor	TS	Vim Mode	Run on Ctrl+S	Pre-Styled	Extras	Since
profrontend.dev	⚠️ Partial	❌	47	❌	Sandpack	CodeMirror	❌	❌	❌	❌	❌	Feb 2025
greatfrontend.com	⚠️ Partial	✅ Server	141	Many	Sandpack	Monaco	✅	❌	❌	❌	Quizzes, katas, blog, other libraries	+10 Years
reactpractice.dev	⚠️ Partial	⚠️ Partial	20	❌	No	No	❌	❌	❌	❌	Blog, feedback	Jan 2023
reacterry.com	✅ Free	✅ Client	29	95	Sandpack	Monaco	❌	❌	❌	❌	JS challenges, quizzes, theory	Mar 2023
reactchallenges.live	✅ Free	❌	6	❌	CodeSandbox	External	❌	❌	❌	❌	❌	May 2022
hackerrank.com/domains/react	⚠️ Partial	✅ Server	10	✅	CodePair	Monaco	❌	❌	❌	✅	Other libraries, languages, certifications	+10 Years
reactchallenges.com	⚠️ Partial	✅ Server	40	❌	Sandpack	Monaco	✅	✅	✅	✅	Solution code and preview, save attempts	Nov 2025
frontend-challenges.com	✅ Free	❌	29	81	Sandpack	Monaco	⚠️ Partial	❌	❌	❌	Theory, quizzes, katas	Jan 2024
clientside.dev	⚠️ Partial	✅ Server	20	37	Sandpack	CodeMirror	❌	❌	❌	❌	Quizzes, katas	Sep 2019
acecodinglab.com	⚠️ Partial	✅ Client	14	❌	Sandpack	CodeMirror	❌	❌	❌	❌	❌	Sep 2024
reactprep.dev	⚠️ Partial	✅ Client	52	❌	Sandpack	CodeMirror	✅	❌	❌	❌	Explanation, solution	Nov 2024

Notes

Test Types

Client tests (Browser / Sandpack Tests)

Some platforms run tests directly in the browser using environments like SandpackTests, a thin wrapper around Jest.

This allows running tests without a server, but comes with important limitations:

• Only supports basic configurations.
• Cannot use many Node APIs or native dependencies.
• Tests must remain relatively simple due to browser constraints.

Server tests (Full Jest / Node environment)

Other platforms run tests on a real server using full Jest or an equivalent Node environment. This allows:

• Testing more complex and realistic scenarios.
• Using any Node dependency.
• Testing advanced logic, multiple files, complex mocks, external libraries, etc.

In summary:

• Client tests → fast but limited; suitable for simpler challenges.
• Server tests → full-featured and much closer to real-world development conditions.

Editor: Monaco vs CodeMirror

Monaco Editor (used by VS Code) includes a full TypeScript worker, which provides:

• Real-time type checking
• Autocomplete and IntelliSense
• Error diagnostics as you type
• More accurate refactoring and navigation tools

CodeMirror, on the other hand, does not ship with a TypeScript worker by default.

This means:

• No real-time type checking
• No true TypeScript autocomplete
• Limited or no IntelliSense-like features

In practice, this makes Monaco significantly more powerful for TypeScript-heavy or production-like React workflows.

Note on “Run on Ctrl+S”

Some platforms re-evaluate your code on every keystroke.

This means that while you're still typing — for example, before finishing a line or closing a bracket — the preview tries to render the incomplete code, often resulting in temporary errors or a broken UI.

This creates a janky experience that doesn’t resemble how you normally work in a real editor.

Platforms that support Run on Ctrl+S behave much closer to a real development workflow:

• The code is only re-evaluated when you manually save (Ctrl+S).
• You can type freely without the preview breaking.
• The flow feels similar to VS Code or any local setup.

Know another React challenge platform? Share it in the comments and I’ll update the table.

Comments

[Duffman]

updated with reactprep.dev