Load non-critical code when content approaches the viewport
SkillDev toolsImport claude skill guidance for pages that load expensive modules only when they become visible. It is a skill that helps balance early enough loading for smooth scrolling against keeping the initial route light when reviewing long pages, dashboards, or content feeds with offscreen modules.
Available today. Use it from your connected AI after setup.
No other account needed.
Have a long page, dashboard, or content feed that uses expensive offscreen modules.
Then ask your AI: use the Load non-critical code when content approaches the viewport skill
What your AI can do with it
- Advise when to load expensive offscreen modules on long pages
- Balance smooth scrolling against a light initial route
- Apply to dashboards and content feeds with heavy modules
- Guide import-on-visibility decisions during page reviews
Getting started
- Have a long page, dashboard, or content feed that uses expensive offscreen modules.
- Add the import-on-visibility skill to the agent's available skills.
- Ask the agent to review the page and apply the skill's loading guidance.
- Adjust module loading based on the balance it recommends between early loading and initial route weight.
What this skill tells your AI
The instructions your AI receives, as published by thedaviddias/front-end-checklist in skills/import-on-visibility/SKILL.md and read by ahel’s review.
Many pages ship JavaScript for offscreen sections that a user may never reach. Import-on-visibility keeps the initial route lighter while still loading content early enough to feel ready when users scroll to it.
Quick Reference
- Use Intersection Observer to start loading code before an offscreen section becomes visible
- Reserve space with placeholders or skeletons so deferred sections do not cause layout shift
- Tune
rootMarginso heavy content loads early enough without competing with above-the-fold work - Use this for charts, reviews, related products, embeds, and offscreen dashboards
Check
Identify components, widgets, or modules that load on first render even though they only appear after the user scrolls. Flag which ones can switch to visibility-based loading.
Fix
Use Intersection Observer or an equivalent framework primitive to load the offscreen component or dependency when it approaches the viewport, while preserving layout stability and a clear placeholder.
Explain
Explain import-on-visibility, how it differs from import-on-interaction, and how viewport-based loading helps large pages stay fast.
Code Review
Inspect scroll-triggered sections, embeds, charts, recommendation modules, and long landing pages. Flag code that is bundled eagerly even though the corresponding UI stays offscreen until later, and verify the deferred version still loads before the user reaches it.
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/en/rules/performance/import-on-visibility
Signals
- GitHub stars
- 74k
- Forks
- 7k
- Last commit
- Aug 2026
Questions
- When should this skill be used?
- Use it when reviewing long pages, dashboards, or content feeds that contain expensive offscreen modules.
- What problem does it solve?
- It balances loading modules early enough for smooth scrolling against keeping the initial route light.
- Does it apply to dashboards?
- Yes, dashboards and content feeds with expensive offscreen modules are among its intended use cases.
Advanced
- Item type
- skill
- Key
import-on-visibility- Source
- github.com/thedaviddias/front-end-checklist