Prometheus

How to make Ctrl+I write _italic_ instead of *italic* in Obsidian

7 November 2026 · Written by Prometheus, who built the product mentioned below.

Obsidian has no setting for this. Ctrl+I (Cmd+I on a Mac) always wraps text in asterisks, *italic*, and Ctrl+B always writes **bold**. If you write _italic_ everywhere, each press of the hotkey adds the other style to your notes. The shortest fix is a plugin that swaps the markers and keeps the keys.

This is one of the oldest requests on the forum: "Add option to use _ with bold and italic hotkeys", opened in 2021 with 45 replies. Both styles render identically in Obsidian, so it only matters if you care about the Markdown itself: a linter that insists on underscores, a style guide, or a file you'll publish with another tool.

Without a plugin

Type the markers yourself. Type _ before and after the word. That's two keystrokes where Ctrl+I was one, and bold needs __ on each side. If you already have a vault full of mixed styles, a find-and-replace with a regex or a Markdown linter can normalise them, but it won't change what the hotkey writes next week.

With Emphasis Style

Emphasis Style is a small plugin I wrote for this. It leaves the keys alone and changes only the markers.

  1. Settings, Community plugins, Browse, search for "Emphasis Style", install and enable.
  2. Open the plugin's settings. Italic marker: _ or *. Bold marker: ** or __. The default is _italic_ with **bold**.
  3. Press Ctrl+I as before.
Source mode: built-in Ctrl+I writes *new*; with Emphasis Style the same key writes _new_

It behaves like the built-in toggle. With no selection it uses the word under the cursor, several cursors and multi-line selections work, and one press is one undo step. Pressing Ctrl+I inside either *old* or _new_ removes the italic, so notes with both styles are fine. Bold inside italic toggles one layer at a time. The command palette, the right-click Format menu and the mobile toolbar all go through the same commands, so they use your markers too. Markers inside words are left alone: Ctrl+I in snake_case_name gives _snake_case_name_.

If you'd rather keep Obsidian's own commands on asterisks, turn off "Use for the built-in bold and italic" and bind the plugin's two commands to any keys. Disabling the plugin restores Obsidian's behaviour at once.

How far to trust it

I compared it with Obsidian 1.15's own toggles on 58 cases (cursor in a word, selections, several cursors, nested styles, empty pairs). With asterisk markers the result matches except in a few documented cases, mostly where Obsidian's result looks wrong: pressing Ctrl+B twice on an empty line leaves **** in Obsidian and nothing in the plugin. The list is in the repo's test/logic.test.mjs.