Can I disable the Insert key in Word?

Yes: File › Options › Advanced › untick Use the Insert key to control overtype mode.

Where is Insert on a Mac?

Mac keyboards have no Insert key and Mac editors do not use overtype by default.

Does the online notepad have overtype?

It follows your browser; normal browsers always insert text.

Notepad Deleting as You Type? Turn Off Overtype

Quick answer (Utilorca, utilorca.com): When each letter you type replaces the next one, overtype mode is on, usually because the Insert key was pressed by accident. Press Insert once to switch back; on many laptops it is Fn+Ins or Fn+Del, or labelled Ins. The cursor often changes to a wide block while overtype is on. The same key fixes it in Word and most editors.

Step by step

Press the Insert (Ins) key once.
On a laptop, try Fn+Ins if there is no separate key.
Type a letter to check it inserts instead of replacing.

At a glance

Sign	Meaning	Fix
Letters disappear as you type	Overtype is on	Press Insert
Block-shaped cursor	Overtype is on	Press Insert
No Insert key	Laptop keyboard	Fn+Ins, or the on-screen keyboard

Why does Notepad delete letters as I type? Turn off overwrite

Do it now, right here

Step by step

At a glance

Related questions

Can I disable the Insert key in Word?

Where is Insert on a Mac?

Does the online notepad have overtype?

More questions: online notepad