How do I highlight the column just past my textwidth to visually mark line length limits?

Explanation

The colorcolumn option highlights one or more vertical columns to help keep lines within a length limit. Values prefixed with + or - are relative to textwidth, so the guide column automatically follows if you ever change your line length setting.

How it works

• set colorcolumn=80 — absolute: always highlights column 80
• set colorcolumn=+1 — relative: highlights the column one past textwidth
• set colorcolumn=-0 — highlights exactly at textwidth

With set textwidth=79, set colorcolumn=+1 highlights column 80. If you later do set textwidth=119, the highlight automatically moves to column 120 without touching colorcolumn.

Example

set textwidth=79
set colorcolumn=+1

Column 80 is now highlighted in a different color. Any text reaching that column is clearly past the limit. After set textwidth=99, column 100 becomes highlighted instead.

Tips

• You can highlight multiple columns: set colorcolumn=+1,+2,+3 to show a gradient zone
• Customize the highlight color with :hi ColorColumn guibg=#333333
• Use set colorcolumn= (empty) to disable the highlight entirely
• The relative form only works when textwidth is non-zero; otherwise it has no effect
• Combine with set wrap and set linebreak for a visual guide that complements soft wrapping