Provide an offline fallback page

SkillDev tools

offline-fallback is a skill that guides an AI agent through providing a custom offline fallback page for a website. Instead of the browser's default "No internet connection" screen, users see a branded page that can surface cached content or queue actions. It covers creating the page, pre-caching it in a service worker, and serving it for failed navigation requests.

Available today. Use it from your connected AI after setup.

Have a web project where a service worker can be added or already exists.

Then ask your AI: use the Provide an offline fallback page skill

What your AI can do with it

  • Create a self-contained /offline HTML page that works without network requests
  • Pre-cache the offline page during the service worker install event
  • Configure the fetch handler to serve the offline page for failed navigation requests
  • Review service worker code to verify the fallback is only served for navigation requests
  • Explain how service workers intercept failed requests and return cached pages
  • Check whether a site shows a custom offline fallback page when disconnected

Getting started

  1. Have a web project where a service worker can be added or already exists.
  2. Load the offline-fallback skill so the agent can follow its rule guidance.
  3. Ask the agent to create a minimal /offline page and pre-cache it at service worker install.
  4. Have the agent update the fetch handler to serve the offline page for failed navigation requests.
  5. Test by disconnecting the network and loading a page to confirm the fallback appears.

What this skill tells your AI

The instructions your AI receives, as published by thedaviddias/front-end-checklist in skills/offline-fallback/SKILL.md and read by ahel’s review.

The browser's default offline error screen ("No internet connection") is confusing and completely outside your brand. A custom offline page maintains the user experience, reinforces trust, and can surface cached content or useful actions — such as enabling users to continue reading a cached article or queuing a form submission for later.

Quick Reference

  • Create a minimal /offline HTML page that works without any network requests
  • Pre-cache the offline page during the service worker install event
  • Intercept failed navigation requests and serve the offline page instead
  • Include helpful guidance so users know what to do while offline

Check

Check whether the site shows a custom offline fallback page when the network is disconnected and a navigation request cannot be fulfilled.

Fix

Create a self-contained /offline page and configure the service worker to pre-cache it and serve it for failed navigation requests.

Explain

Explain how a service worker can intercept failed network requests and return a cached offline fallback page to the user.

Code Review

Review the service worker fetch handler and the offline page markup. Verify the offline page is pre-cached at install time, that it does not depend on external resources, and that the fallback is only served for navigation requests (not sub-resources).


For full implementation details, code examples, and framework-specific guidance, see references/rule.md.

Rule page: https://frontendchecklist.io/en/rules/performance/offline-fallback

Signals

GitHub stars
74k
Forks
7k
Last commit
Aug 2026

Questions

What does the offline fallback page do?
It replaces the browser's default offline error screen with a custom page that maintains the user experience and can surface cached content or useful actions, like continuing to read a cached article or queuing a form submission.
When should this skill be used?
When adding PWA capabilities, implementing a service worker, or improving the experience for users on unreliable network connections.
Advanced
Item type
skill
Key
offline-fallback
Source
github.com/thedaviddias/front-end-checklist