Overwritemode

Overwritemode is a mode in text editing software where typed characters replace existing characters to the right of the cursor instead of being inserted at the cursor position. When enabled, each keystroke overwrites the character currently under the cursor and then moves the cursor forward by one position.

In overwritemode, typing a character does not increase the length of the document; it replaces the character at the cursor with the new character and advances the cursor. If multiple keystrokes are entered, successive characters overwrite subsequent characters in sequence. This contrasts with insert mode, where typing inserts new characters and shifts existing text to the right.

The mode is commonly toggled on and off, often via the Insert key or a status indicator in the application’s user interface. Some editors display an on-screen marker (for example, a toggle label or a different cursor shape) to indicate that overwritemode is active. In modern software, overwritemode may be disabled by default or be available as an optional feature for compatibility with older workflows.

Usage and implications: overwritemode can be useful for fixed-width editing, quick corrections, or when exact character replacement is needed without altering surrounding layout. However, it can lead to accidental data loss if users are unaware that typing will replace existing text. Users transitioning from insert mode should understand the current mode indicator to avoid unintended edits.

See also: insert mode, overstrike, insert key, text editor conventions.