The Event Loop, Visualized
Watch the JS event loop run your code, step by step
Get picks like this daily. Today's launch numbers, the top launches, AI and tech news, and a daily opportunity pick, straight to your inbox.
Want to reach these readers? Sponsor an issue.
Most event loop explainers are static diagrams. This one runs. Watch the call stack, Web APIs, microtask queue and task queue animate your code tick by tick: forward, backward, at any speed. - Paste your own snippet (setTimeout, promises, async/await, queueMicrotask) and simulate it - One animation, three explanations: simple, developer, or straight from the HTML spec - Ready-made scenes like Promise vs setTimeout and microtask starvation - Interview questions to test yourself
PH · launched Sep 29, 2026 · 2 upvotes (top 26%) · 0 views
Niche: codebase visualization tools · 89 launches, 4 in the last 7 days ▼ -43% · Explore this niche →
Category and tags
- Horizontal
- Dev tools
- Developer
- Not AI
- Hobby / open-source project
- Education
- Software Engineering
- Developer Tools
Visit website ↗ Source listing ↗
More like this: all 89 launches in codebase visualization tools →
Could you build this?
Partial While simple animations of static code are vibe-codeable, building a true step-by-step debugger and AST interpreter that simulates JavaScript execution (call stack, microtasks, timers) requires deep language runtime internals knowledge.
What it would actually take: The core requires an AST parser (like Babel or Acorn) and a customized JavaScript runtime environment/interpreter (similar to JS-Interpreter) instrumented to record execution ticks, promise resolution states, and task queue shifts. Each step must produce a serializable state snapshot to support bi-directional timeline scrubbing. Mastery of the ECMAScript event loop specification and custom virtual machine execution loops is necessary.
Competitors
Other products that read as similar to this one : 84 launches clear the similarity bar, closest 8 shown.
Attention rank: #27 of 85 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).
Launched 284 days after the earliest competitor.
- Code Visualiser · ph · 2026-09-28 · 2 upvotes · similarity 0.54
- Hacktimer · ph · 2026-10-12 · 1 upvotes · similarity 0.46
- Tickdown · ph · 2026-10-17 · 1 upvotes · similarity 0.42
- An event loop for asyncio written in Rust · hn · 2026-03-21 · 5 upvotes · similarity 0.42
- Nexa Flow · ph · 2026-10-22 · 2 upvotes · similarity 0.41
- code-slowmo · github · 2026-10-20 · 18 upvotes · similarity 0.40
- Looped In · ph · 2026-11-03 · 1 upvotes · similarity 0.40
- QuickBEAM · hn · 2026-03-28 · 113 upvotes · similarity 0.39
The niche, labels, vibe code rating and competitor comparison on this page are analysis by Nicheloom. If you use them, please credit nicheloom.com. How you may use our data.