Google announced its new Gmail web app back in late April, and this week it picked up native offline support, thanks to its use of Progressive Web App (PWA) technologies.
“[You can] read, respond to, and search your Gmail messages even when you aren’t connected to the Internet,” a Gmail Help document explains.
This new functionality, which I found out about thanks to 9to5Google—I don’t believe there’s an official announcement—marks the first time that Gmail has natively support offline usage. But it’s not the first time that Google has enabled this feature: A special Gmail Offline web app for Chrome was available previously, and Gmail users could also enable offline support via a browser extension.
Offline support in the new Gmail is currently available only in Chrome. To enable it, make sure you’re using the new Gmail. Then, open Gmail settings and check the option “Enable offline mail.” From there, you can configure other related settings, including the number of days of messages you would like to sync. Messages sent while offline will be stored in a new Outbox folder until you’re online again.
Google also recommends that you load Gmail before your PC goes offline.