Vivix is a free, open-source JavaScript execution visualiser that runs entirely in your browser.
Most tools show you what your code outputs. Vivix shows you how it executes step by step, instruction by instruction.
Watch in real time as:
- The call stack grows and shrinks frame by frame
- Heap memory mutates as objects are allocated
- async/await suspends a function, tears down the stack frame, queues a microtask and reconstructs execution
No install. No account. No server. Your code never leaves your machine everything runs client-side via a Web Worker.
Built with Svelte 5, Acorn AST, CodeMirror 6, and GSAP. 12 guided modules covering variables, closures, async/await, promises, event listeners, and more. 490 passing tests.
Used by 1,399 developers across 88 countries.
