Developer Tools
Free online tools for developers. No signup required — use instantly in your browser.
Big O Calculator
Instantly calculate time complexity for any input size. Compare O(1) to O(n!) with operation counts and estimated runtimes.
JSON Formatter
Format, minify, and validate JSON online. Syntax highlighting, configurable indentation, and instant error detection.
Regex Tester
Test regular expressions with real-time matching, flag controls (g/i/m/s), and detailed match information.
Algorithm Visualizer
Watch 15+ algorithms animated step-by-step with 2D/3D views. Sorting, searching, graph traversal, trees, and data structures.
System Design Diagram
Build system architecture diagrams with drag-and-drop nodes: servers, databases, load balancers, caches, queues, and more.