How To Enable Offline Mode For Google Docs
Google Docs, Sheets, and Slides can be used in offline mode. The changes made when offline will automatically be saved and synced once back online. This is applicable only when using Google Chrome browser and browsing in regular mode (not private mode).
Here is how to enable it:
Open Google Drive and click on the gear icon to access Settings.
From the General section, scroll down to the Offline option...