hackable javascript testing
for the 21st century


A tool to see the execution of plain and simple javascript code


To put test code on the foreground


Using modern browsers' immense capabilities: iframes for sandboxing, javascript parsers in javascript, not-so-evil evals, web storage, etc.

Written for JS API authors

yolpo is a tool and a web site for javascript API authors. The tool looks a bit like a video player but it runs javascript. Use it to present your javascript code or to test your API or both.

A new interpreter

At its core, yolpo is a statement-by-statement javascript interpreter. This means that it does not 'eval' code in its entirety. Instead, it starts by executing the first statement and continue by executing all statements in sequence. This is the most natural way of presenting a program and a great fit for error discovery too.

GitHub integration

Use Gist GitHub to store code; then get yolpo to run it.