How do I collapse multiple consecutive spaces into a single space throughout a file?

Explanation

The pattern \s\+ matches one or more whitespace characters (spaces, tabs). Replacing it with a single space throughout the file cleans up double-spaces, mixed tabs-and-spaces, and any other whitespace clutter — a common need when processing pasted text, legacy files, or data exports.

How it works

• % — the range covering the entire file
• s/ — substitute command
• \s — any whitespace character (space or tab, equivalent to [ \t])
• \+ — one or more occurrences
• — replace with a single space
• /g — global flag: replace all occurrences on each line

Example

Before:

name:    Alice      age:   30    city:     New York

After :%s/\s\+/ /g:

name: Alice age: 30 city: New York

To also strip leading and trailing whitespace on each line, chain it:

:%s/^\s\+//e | %s/\s\+$//e | %s/\s\+/ /g

Tips

• The e flag suppresses errors on lines where the pattern is not found — safe to add when combining multiple substitutions
• To normalize only within a visual selection (not the whole file): :'<,'>s/\s\+/ /g
• If you only want to collapse spaces (not tabs), use \+ (two spaces then \+) or \ \+ instead of \s\+
• For a more thorough cleanup, :retab converts tabs to spaces (or vice versa) based on your tabstop setting, and can be combined with this substitution