Your users are no longer sitting at their desktops, with a wire connecting them to the internet. They are visiting your site from a phone in an elevator, from their tablet on the subway, or on their laptop while they sit cramped into seat 25 E. This is why modern browsers support service workers, a new technology which lets you serve your content to your users, even when they are offline. UpUp is
![UpUp - Offline First in 1 line of Javascript](https://cdn-ak-scissors.b.st-hatena.com/image/square/afc3504d36d62eb50ad555545c78371a7e9a1d1a/height=288;version=1;width=512/https%3A%2F%2Fwww.talater.com%2Fupup%2Fimg%2Fupup-screenshot.jpg)