Recursive is a open-source tool that lets you paste your code and watch it execute line by line. No setup, no breakpoints — just paste and run. Try it out → What it does Paste a function (or plain code) and it runs step by step Variables are tracked and displayed at every step Arrays are shown as a grid with per-cell change highlighting Recursive functions are visualized as a call tree Parameters are auto-detected — just fill in the values and hit run Quick example Paste this Python code: def bubble_sort(arr): n = len(arr) for i in range(n): for j in range(0, n - i - 1): if arr[j] > arr[j + 1]: arr[j], arr[j + 1] = arr[j + 1], arr[j] return arr Enter [5, 3, 8, 1, 2] as the argument, hit run, and step through the execution. You'll see exactly how the array changes at each swap. Supports Python and JavaScript, TypeScript Python — standard library works out of the box (collections, functools, itertools, etc.) JavaScript / TypeScript — types are stripped automatically, built-in APIs all work Embed anywhere You can embed the execution view in your blog, Notion, or Obsidian: Great for algorithm tutorials or study notes. Open source The entire project is open source. Feature requests, bug reports, and PRs are welcome. GitHub: github.com/oilater/recursive Issues: Issues If you found it useful, a ⭐ on GitHub would mean a lot!