Online Tool Store
Async/Await Flow Visualizer
Enter an async function with sequential awaits to see a step-by-step timeline of when each operation starts and resolves. Runs entirely in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Example
Async/Await Flow Visualizer
Sample: 3 sequential awaits
Example shown — replace it with your own async function.
async function run() {
const a = await fetchA();
const b = await fetchB(a);
return await fetchC(b);
} Result
t=0ms: fetchA() starts, execution pauses
t=120ms: fetchA resolves, fetchB() starts
t=260ms: fetchB resolves, fetchC() starts
t=340ms: fetchC resolves, function returns
How it works
- Enter an async function with a sequence of awaits.
- Each await point is stepped through.
- See a timeline of when each step starts and resolves.
The method
Each await point pauses the timeline until its promise resolves, then the next step begins, illustrating how sequential async operations actually execute over time.
FAQ
Why does execution pause at each await?
The await keyword suspends the async function until the awaited promise resolves, handing control back to the event loop in the meantime, rather than blocking the whole program.
Does this show parallel awaits too?
This example shows sequential awaits; awaiting Promise.all() for parallel operations would show a different, overlapping timeline.
Does this run my actual code?
No — this visualizes the timing pattern step by step for illustration; run your real code in your own environment to see actual timing.
How we compare
| Feature | Online Tool Store | console.log timestamps | Reading the code mentally |
|---|---|---|---|
| No software install | Yes | No | Yes |
| Quick to start | Yes | Setup required | Fast but error-prone |
| Free to use | Yes | Free | Free |
For understanding async timing without adding temporary logging, this gives a clearer picture faster.