The Overwrite Frustration
When typing in Google Docs, you generally expect new characters to push existing text to the right. Occasionally, you might find that as you type, Google Docs automatically deletes the letters immediately in front of your cursor, replacing them with your new keystrokes. This is not a bug within Docs itself, but rather a system-level toggle that you have accidentally activated. You have switched your cursor from the standard “Insert” mode (where new text is squeezed in) to “Overtype” mode (where new text overwrites existing text).
Restoring Insert Mode
To stop Google Docs from automatically deleting text as you type and return your cursor to its normal behavior, you simply need to press a specific key on your physical keyboard.
The culprit is almost always the Insert key (often abbreviated as Ins). On a full-sized Windows desktop keyboard, it is usually located above the directional arrow keys, near the Home and End buttons. On a laptop, it might share a key with another function and require you to hold the “Fn” (Function) key simultaneously. Simply press the Insert key once. There will be no on-screen notification in Google Docs, but if you click back into your document and begin typing, you will see that the text no longer overwrites the characters ahead of it. The cursor has returned to standard Insert mode.