Use scheduler.yield() to keep the main thread responsive during long tasks
SkillDatabases & datascheduler-yield is a skill that guides an AI agent when reviewing JavaScript that performs synchronous loops over large datasets, recursive tree traversals, or bulk DOM updates that may exceed 50 ms on mid-range devices. It helps the agent spot slow loops and heavy page work so code stays responsive.
Available today. Use it from your connected AI after setup.
No other account needed.
Have an AI agent that can load skills.
Then ask your AI: use the Use scheduler.yield() to keep the main thread responsive during long tasks skill
What your AI can do with it
- Reviews synchronous loops over large datasets for responsiveness
- Reviews recursive tree traversals that may block the page
- Reviews bulk DOM updates for long-running work
- Flags JavaScript that may exceed 50 ms on mid-range devices
- Guides the agent to spot slow loops and heavy page work
Getting started
- Have an AI agent that can load skills.
- Add the scheduler-yield skill to the agent's available skills.
- Ask the agent to review JavaScript with synchronous loops, recursive traversals, or bulk DOM updates; the skill applies when that work may exceed 50 ms on mid-range devices.
What this skill tells your AI
The instructions your AI receives, as published by thedaviddias/front-end-checklist in skills/scheduler-yield/SKILL.md and read by ahel’s review.
Any JavaScript task longer than 50 ms blocks the browser's main thread, preventing it from processing clicks, keyboard events, and rendering frames. Yielding between chunks of work keeps Interaction to Next Paint (INP) low and makes the page feel responsive even during heavy computation.
Quick Reference
- Tasks longer than 50 ms block input and hurt Interaction to Next Paint (INP)
- scheduler.yield() pauses execution, lets the browser handle queued input, then resumes
- Use a MessageChannel-based polyfill where scheduler.yield() is unavailable
- Apply to data processing loops, tree traversals, and bulk DOM mutations
Check
Identify synchronous loops, recursive traversals, or bulk operations in this code that could run for more than 50 ms and block user input.
Fix
Refactor long synchronous tasks to yield to the browser between chunks using scheduler.yield() with a MessageChannel fallback.
Explain
Explain why tasks longer than 50 ms hurt INP, how scheduler.yield() works, and when to use it versus Web Workers.
Code Review
Review event handlers, data transformation functions, and initialization routines for synchronous loops over large collections that could block input. Flag any loop where the total work could exceed 50 ms.
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/en/rules/javascript/scheduler-yield
Signals
- GitHub stars
- 74k
- Forks
- 7k
- Last commit
- Aug 2026
Questions
- When should the agent use this skill?
- When reviewing JavaScript that performs synchronous loops over large datasets, recursive tree traversals, or bulk DOM updates that may exceed 50 ms on mid-range devices.
- What does the skill do for the agent?
- It guides the agent to spot slow JavaScript loops and heavy page work so code stays responsive.
- Does it run the code or measure performance?
- The item only describes reviewing JavaScript and spotting slow loops and heavy page work; it does not mention running code or measuring performance.
Advanced
- Item type
- skill
- Key
scheduler-yield- Source
- github.com/thedaviddias/front-end-checklist