Underliner

Ctrl+U to underline. Press it again to take the underline away.

Obsidian gives bold and italic a hotkey but not underline, because Markdown has no underline syntax. The only way is raw HTML:

This sentence has one <u>underlined</u> phrase in it.

Seven characters typed around every phrase, closed every time, forgotten often enough to be irritating. Underliner turns that into a single keystroke, and a toggle.

What it does

Why this isn't a five-line snippet

Because the naive version breaks on real notes.

• An inline HTML tag cannot span a line break. Wrapping a multi-line selection in one <u>…</u> silently breaks the rendering of the paragraph around it. Underliner wraps each line separately and leaves leading whitespace outside the tag, so it keeps working inside list items and blockquotes.
• Pressing the hotkey twice should be a no-op. Underliner detects a surrounding pair — or any <u> pair contained in the selection — and removes it instead of nesting another one.
• Nothing selected shouldn't do nothing. With the cursor inside a word, that word is wrapped — no need to select it first. On blank space it inserts an empty pair and drops the cursor between the tags.

Word detection covers ASCII words (letters, digits, _, -, '). It deliberately skips CJK text: Chinese and Japanese have no spaces, so guessing a word boundary there would wrap the wrong range — you get an empty pair to type into instead.

Install

Community directory

Submitted and under review. Once it's listed, install it from Settings → Community plugins → Browse.

BRAT (before that)

1. Install and enable BRAT.
2. Run the command BRAT: Add a beta plugin for testing.
3. Enter guguthecoder/obsidian-underliner.

Manual

1. Download main.js and manifest.json from the latest release.
2. Put them in <vault>/.obsidian/plugins/underliner/.
3. Reload Obsidian, then enable Underliner in Settings → Community plugins.

Hotkey

Ctrl+U (⌘+U on macOS) is bound as a default, so it works the moment the plugin is enabled. If something else claims it, rebind it in Settings → Hotkeys → Underliner: Toggle underline. On mobile, add the command to the editor toolbar in Settings → Mobile.

Already using another underline plugin?

There are older plugins that write <u> too. If one of them does everything you need, keep it — this isn't meant to replace something that already works.

It exists for the cases those ones get wrong, and which are still open issues in their trackers: the underline doesn't come off when you press the hotkey again, the toggle toggles something unexpected, a multi-line selection renders broken, the cursor inside a word does nothing, or a word at the end of a line is skipped.

Compatibility

• Obsidian 1.4.0 and later, desktop and mobile.
• Source mode, Live Preview and Reading view.
• Only edits text when you run the command — the selection, or the word under the cursor. Notes are never modified on load.
• Uninstalling leaves the <u> tags in your notes, as it should: they're ordinary text, and Obsidian renders them without any plugin.

Design notes

The plugin is a single 4.5 KB main.js with no dependencies, no settings tab, no stylesheet and no build step — open it, edit it, reload Obsidian. Underlining is native HTML, so the rendering is already there; there is nothing to style.

Underliner deliberately does not add a toolbar button, a formatting menu entry, a live-preview decorator, or tags like <center> / <sub> / <sup>. Those are the features that turn five kilobytes into five thousand lines.

License

MIT