# Change Edit settings in CotEditor on Mac

Use Edit settings in CotEditor to choose how the editor behaves while editing.

To change these settings in the CotEditor app on your Mac, choose CotEditor > Settings, then click Edit.

Indentation
Option | Description
--- | ---
Prefer using spaces/tabs | Set the character to use for indentation and the Tab key input. Choose one of the following: Spaces: Insert multiple space characters according to the indent width setting for a single indentation. Tabs: Insert a single tab character for a single indentation.
Indent width | Set the number of spaces to which a tab character is expanded.
Detect indent style on document opening | Detect whether the indent style of the opened document is spaces or tab, and automatically set whether expand tab input into spaces on the document. If there are not enough indented lines for detection, the default setting is used.
Automatically indent while typing | New lines are automatically indented by hitting the `Return` or `Enter` key, and the new line begins at the same indentation point as the previous line.
Indent selection with Tab key | On the `Tab` key pressed with text selection, the selections are indented instead of replacing the selection with indent whitespace. Likewise, on the `Tab`-`Shift` keys pressed, the selections are outdented.

Whitespace
Option | Description
--- | ---
Automatically trim trailing whitespace | Whitespaces at the end of lines are removed automatically while typing.
Including whitespace-only lines | Trimming action removes all whitespaces in whitespace-only lines

Content parse
Option | Description
--- | ---
Link URL in document | Highlight and make clickable the URLs found in the document.
Highlight matching braces “()” “[]” “{}” | Briefly highlight the corresponding brace when the insertion point moved through a part of paired braces.
Highlight “<>” | Apply paired brace highlight also to angle brackets.
Highlight instances of selected text | Highlight all the occurrences of the selection in the editor with a time delay after selecting text. The highlight performs only when the selected text consists of entire words.

## See also

- Change settings