--- name: offline-fallback description: "Use when adding PWA capabilities, implementing a service worker, or improving the experience for users on unreliable network connections." metadata: category: performance priority: low difficulty: beginner estimatedTime: "20" source: frontendchecklist.io url: https://frontendchecklist.io/en/rules/performance/offline-fallback --- # Provide an offline fallback page 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