You can generate an HTML and JSON backup of your account data using the export feature.
The HTML export contains all your tasks, list, to-dos, discussions, estimates, files etc. Download the Zip archive and open the "index.html" file.
You can also export the data in JSON format which is ideal for transferring data between systems.
Exporting data is only available to admin users and the account owner.
To export the data open a project and open the settings window.
Open project settings
Navigate to the "Export" tab