Using Todoist offline is a great way to stay organized anywhere, any time. 
Todoist offline mode is automatically activated whenever you don’t have access to the internet.
Any changes that you make in Todoist while offline will be automatically synced with the server as soon as you reconnect to the internet.
Before going into offline mode, please ensure that you’re logged in to your Todoist account, as you cannot log in to the app while offline, and that the app is launched if you're accessing the web or desktop version.

Use Todoist while offline