Remove extra spaces

Start by identifying the space

Two gaps that look alike can contain different characters. Ordinary spaces are U+0020. Tabs are U+0009. A non-breaking space is U+00A0. Repeated ordinary-space cleanup only changes the first category; that precision prevents an unrelated character from being removed by accident.

The inspector identifies tabs and non-breaking spaces. You can then decide whether each represents unwanted pasted formatting or something worth preserving.

Clean prose with a small, clear rule

In prose, a run of ordinary spaces is often accidental. With Collapse repeated spaces enabled:

Before: Clear   text    is useful.
After:  Clear text is useful.

Trim line edges separately removes ordinary spaces and tabs at the beginning and end of each line. Tidy prose combines these with reduction of excessive internal blank lines. It does not change letter case or punctuation.

Keep indentation and Markdown spacing when it matters

Spacing can represent document structure. Leading indentation may be significant in code or a nested list. Two trailing spaces can create a Markdown hard break. A table may rely on runs of spaces to align its columns.

First line··
Next line

Here, the two visible dots illustrate trailing ordinary spaces; they are not literal characters in the document. Trimming those spaces can change Markdown interpretation. Choose Keep layout before cleaning code or Markdown, or turn off the specific rule that removes meaningful spaces.

Downloading as Markdown does not undo cleanup. It only saves the current result with an .md extension.

Non-breaking spaces are a separate decision

A non-breaking space can keep related text together across line wrapping. Converting U+00A0 to an ordinary space preserves a gap but changes that wrapping behavior. That conversion is off initially.

If Hello world contains U+00A0, repeated ordinary-space cleanup leaves it alone. Select Convert non-breaking spaces only when the target application should receive an ordinary space. Narrow non-breaking spaces and other Unicode spaces are not included in this specific rule.

Tabs are not columns

Convert tabs to spaces replaces each tab with one ordinary space. It is not an alignment-preserving tab-expansion tool. A tab may advance to a different visual column depending on the viewer's settings, so replacing it with one space can misalign a table.

Keep layout retains the original tab characters. Compare the result in the application where you will use it if alignment matters.

A practical review

1. Start with Tidy prose for ordinary paragraphs, or Keep layout for structured text.
2. Look at both the start and end of lines, not just gaps between words.
3. Inspect characters if a gap remains after ordinary-space cleanup.
4. Review the clean result before copying, especially for code and Markdown.

The Manual lists the exact rule order. For wrapped prose, see the line-break guide.