Offline Fallbacks

Workbox makes it easy to create robust offline experiences in web applications. When a user navigates to a page without an internet connection, instead of showing an error, your application can serve a predefined fallback page, image or font.

/config/packages/pwa.yaml

pwa:
    serviceworker:
        enabled: true
        src: "sw.js"
        workbox:
            offline_fallback:
                page: 'app_offline_page'
                image: 'images/offline.svg'
                font: 'fonts/normal.ttf'

page_fallback can be a relative URL, a route name or a route name with parameters. See URL parameter for more information.

image_fallback and font_fallback refer to assets delivered by Asset Mapper or an URL to the font file.