Bundles, Cache & Preloading Hints
Understand bundles and caching: content hashes, immutable assets, HTML as the switch. Use gentle preloading to make interactions feel instant.
Bundles, Cache & Preloading Hints is a free React Academy lesson on CoddyKit — lesson 3 of 3. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the React Academy learning path, one of 3 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Why bundles + cache matter
Goal: Ship smaller bundles and let the browser cache them safely.
- Content-hashed filenames
- Immutable cache for assets
- HTML stays short-lived
Cache strategy basics
- Hash filenames: app.3f2a1.js
- Cache-Control: max-age=31536000, immutable
- HTML: short TTL (e.g., no-store or minutes)
- Split rarely-used code
Demo: pre-warm a lazy chunk
Preload on intent: start fetching a lazy chunk early so the next view feels instant.
<div id="root"></div>
Demo: image preload
Preload an image before showing it. When toggled, it appears instantly from cache.
<div id="root"></div>
Preload vs prefetch (concept)
- Preload: high priority for assets needed very soon
- Prefetch: low priority for assets likely needed later
- Use sparingly to avoid network contention
Pitfalls & cache headers
Avoid over-preloading everything. Use content hashes and set immutable caching for bundles; keep HTML short-lived so new hashes deploy quickly.
Caching best practice check
Recap
Recap: Hash your bundle filenames and cache them long. Keep HTML short-lived, and use gentle preload/prefetch to make next views feel instant.
Frequently asked questions
Is the “Bundles, Cache & Preloading Hints” lesson free?
Yes — the full text of “Bundles, Cache & Preloading Hints” is free to read here on the web, and the React Academy course includes 3 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the React Academy course, upgrade to CoddyKit PRO.
What will I learn in “Bundles, Cache & Preloading Hints”?
Understand bundles and caching: content hashes, immutable assets, HTML as the switch. Use gentle preloading to make interactions feel instant. You practise React Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start React Academy?
No prior experience is required. React Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 3 of 3, so you can start here or from the beginning and move at your own pace.
How long does the “Bundles, Cache & Preloading Hints” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this React Academy lesson?
Yes. Every React Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- React.lazy and Suspense — Lazy Components
- Route-based & Component-level Splitting
- Bundles, Cache & Preloading Hints