Is there an autosave feature?

Text editor autosave
In the default Moodle text editor (Atto), the text is automatically saved every 60 seconds.
(Message Draft saved is momentarily shown below the editor window whenever the text is saved.)
If any text has been saved (i.e. after at least 60 seconds of editing), the undo toolbar item* is enabled and the saved text can be restored by clicking on it.
As soon as it is clicked, the redo toolbar item* is enabled.
Clicking on it reverts the text to its previous state.

If the editor window is accidentally closed before the text has been saved to Moodle then, whenever the item is edited again (even in another session in another browser), the saved text is automatically restored.
(A message A draft version of this text was automatically restored is shown below the editor window.)

Note: Text saved by Text editor autosave is not saved to Moodle i.e. the item being edited is not updated.

The alternative TinyMCE editor has a similar feature. Text is saved every 30 seconds.

*Items undo and redo are in the second row of the toolbar menu in HUJI Moodle and in the top row in EXAM Moodle.
The second row can be opened by clicking on item icon at the beginning of the top row..

Quiz autosave
In EXAM Moodle, while a quiz is being attempted, the state of all responses on the current page is automatically saved to Moodle every 60 seconds.
Thus if there is an Essay question, its current state is saved to Moodle.
This becomes the new state of the Essay if the editor window is accidentally closed, or if the quiz is autosubmitted (at its closing time or when it reaches its timelimit)
Note: Unless it becomes the final state, it is not shown in the Response history in the quiz review page.
Only states that are effective when the user changes page or clicks on the Save button (if there is one) are shown in the Response history.

Note: Text editor autosave also works in EXAM Moodle - independently of Quiz autosave.
However, a message is not shown below the editor window when the text is saved by Text editor autosave
Also, if the editor window is accidentally closed, the text stored to Moodle by Quiz autosave is restored - not the text stored by Text editor autosave