JavaScript Event Loop
Interactive visualization of the JavaScript runtime: Call Stack, Web APIs, Task Queue, and Microtask Queue.
Speed
Call Stack
0
Empty
Microtask Queue
0
Empty
Render (rAF)
0
Empty
Timers
0
Empty
I/O
0
Empty
Idle
0
Empty
Execution Statistics
Call Stack: 0
Microtasks: 0
Macrotasks: 0
Timers: 0
I/O: 0
Render: 0
Idle: 0
Current Phase
Waiting for tasks
The animation simulates: placing synchronous code on the Call Stack, scheduling timers and network requests in Web APIs, prioritizing Microtasks (Promise.then) over macrotasks (setTimeout) when the Call Stack is empty, and moving callbacks to the Stack.