I built TraceLit because I was tired of manually dry-running LeetCode problems, especially trees and recursion problems where it’s easy to lose track of execution.

You paste code and input, run it, and step through execution line by line. It helps you see variable changes, control flow, and where things start going wrong.

It’s especially useful for recursion, trees, linked lists, and simulation-style problems.

You can try it here: https://tracelit.dev No signup required.

I’d love feedback on which problem types this feels most useful for, and what feels confusing.