HyperInstant (v2)

HyperInstant is a tiny, dependency-free library inspired by Instant Page.

It speeds up navigation by prefetching internal pages using:

• Hover prefetch (Instant Page style)
• Idle Crawl Prefetch: after the current page is fully loaded, HyperInstant scans same-origin links (menu, buttons, etc.) and prefetches the best candidates one by one, respecting budgets and network safety.

Install

npm i hyperinstant

Usage

Basic

import { init } from 'hyperinstant';

init();

With options

import { init } from 'hyperinstant';

init({
  maxLinksPerPage: 6,
  maxConcurrent: 1,
  enableHover: true,
  enableIdleCrawl: true,
  method: 'link-prefetch', // or 'fetch'
  ignoreSelector: '[data-hyperinstant="ignore"], .no-prefetch',
  onPrefetch: (url, method) => console.log('prefetch', method, url)
});

Opt-out (per link)

<a href="/checkout" data-hyperinstant="ignore">Checkout</a>

How it decides what to prefetch

During Idle Crawl Prefetch, HyperInstant scores internal links:

1. Links in the viewport get highest priority
2. Links inside header/nav get a boost
3. Links that look like CTA buttons get a boost
4. Links with data-hyperinstant-priority="<number>" get extra priority

Then it picks up to maxLinksPerPage links and prefetches them progressively during idle time.

Safety rules

• Respects Save-Data
• Avoids slow connections via navigator.connection.effectiveType
• Stops/aborts when the tab is hidden
• Excludes common action URLs like ?add-to-cart=, /cart, /checkout, /my-account, /wp-admin, etc.

License

MIT