A powerful & high‑speed
time travel debugger

Simple step-through debugging

Simply write/paste your code and press run. A full trace of your code's behavior will be made available to you, like; variables, functions, classes, and all lines that were touched. See which variables were assigned, how and when they were modified.

Step through the program by going forwards and backwards. Feel like you missed a step? Just go back some steps, no need to stop and fully re-run the code. Or just skip all the intermediate steps by immediately stepping to the end to view the output.

Stack frames, scopes & return values

Apart from viewing the touched lines you can also inspect all stack frames and their contents. View all variables, functions and classes within the current scope, or take a look at any previous scope, at any point in time.

Upon returning values in a function, the debugger will create a snapshot right before exiting the function. This way you can view the value that's about to be returned.

Inline debugging support

Do you like using lambdas, arrow/anonymous functions? We've got you covered!

This also enables you to view the steps taken in map, reduce and fold functions as well as LINQ in C#. Thus even tracking multiple "movements" your code might make within a line.

Visualize your code

Add Vector Graphics or Turtle into the mix to be able to view the steps made by your code.

Draw beautiful recursive patterns in Vector Graphics, like a recursive tree. Inspired by the Python Turtle library, Vector Graphics gives you a canvas enabling you to make visualizations, even with languages other than Python.

Or assist a Turtle to fill its appetite, by coding a path towards all available food. Solve a collection of pre‑defined levels, or create your own and share them with your friends!



  • Online IDE for debugging
  • Visual Studio Code extension
  • Github public repository integration for notebooks
  • Access to all programming languages
  • Access to all modules
  • Access to public BETA features
  • 16 Snippets
  • 4 Notebooks



  • Everything included in Free
    • 128 Snippets
    • 32 Notebooks
  • Github public & private repository integration for notebooks
  • Access to private BETA features
  • Support the developer
  • And more to come...

Unleash your debugging powers!

Pick your programming language






Pick your environment


Vector Graphics


Start debugging!