Developer's Playground
Interactive testing and simulation tools for developers including regex tester with visual feedback, JSON validator and formatter with tree view, and markdown editor with live preview for rapid development and debugging.
Regex Playground
Test and debug regular expressions in real-time with visual feedback, match highlighting, and capture group analysis.
JSON Validator & Formatter
Validate, format, and minify JSON with error detection, tree visualization, and customizable indentation.
Markdown Editor
Write and preview Markdown in real-time with split view, quick formatting tools, and download capability.
URL Pattern Matcher
Test URL routing patterns with parameter extraction. Supports Express, React Router, and Vue Router syntax.
HTTP Request Builder
Build and test HTTP requests with custom headers and body content. Supports all HTTP methods.
JavaScript Validator
Validate JavaScript syntax and detect errors before runtime with instant feedback and line numbers.
API Response Simulator
Simulate API responses with custom status codes, delays, and payloads for frontend testing.
Rate Limiter Simulator
Simulate API rate limiting with configurable request limits and time windows. Test 429 responses.
REST API Playground
Complete REST API testing environment with endpoint builder and response visualization.