How do I save screen space by merging the sign column into the line number column in Neovim?

Explanation

Setting signcolumn=number tells Neovim to display signs (diagnostics, git hunks, breakpoints) inside the line number column instead of adding a dedicated extra column beside it. This reclaims a column of horizontal space without losing sign visibility.

How it works

• signcolumn=no — never show signs
• signcolumn=yes — always reserve a fixed column for signs (default in many configs)
• signcolumn=auto — show column only when signs are present (causes layout shift)
• signcolumn=number — signs replace the line number on the lines where they appear; all other lines still show their number normally

When a sign is present on a line, the line number is replaced by the sign icon. When no sign is present, the full line number is shown as normal.

Example

 Before (signcolumn=yes):       After (signcolumn=number):
  1 |  fn main() {              1  fn main() {
  2 | │ let x = 1;              E  let x = 1;    ← sign replaces number
  3 |  let y = 2;               3  let y = 2;

Tips

• This is a Neovim-only option; Vim does not support signcolumn=number
• Works well with plugins like nvim-lspconfig, gitsigns.nvim, and nvim-dap that use signs frequently
• If you use relative line numbers (set relativenumber), the relative number is replaced on signed lines instead
• Combine with set number or set relativenumber for the best experience