How to Underline in Slack (Toolbar and Cmd+U)
Slack does have underline now: select the text and click Underline in the formatting toolbar, or press Cmd+U on a Mac. There is no typed marker for it, so it does not work in markup mode or in bot messages. Steps, where it fails, and what to use instead.
To underline in Slack, select the text in the message box and click Underline in the formatting toolbar, or press Cmd+U on a Mac. Slack's help lists Underline among the toolbar's formatting options, next to bold, italics and strikethrough. Unlike those, underline has no typed marker: underscores make italics, so _text_ is italic, not underlined. That also means you cannot underline with Format messages with markup turned on, and bots cannot send underlined text.
Older guides say Slack has no underline. That was true for years. Slack's help article "Format your messages in Slack" and its keyboard shortcuts page now list it; we checked both on 27 September.
Formatting does not keep you active: Slack still sets you to away after about 10 minutes with no input in the Slack window. Slack Green keeps your dot green from a server during the hours you set.
How to underline text in a Slack message
- Make sure the formatting toolbar is showing under the message box. If it is hidden, click the formatting icon (Aa) in the message field.
- Select the words: double-click a word, or drag across the text.
- Click Underline in the toolbar. On a Mac you can press Cmd+U instead.
- To remove it, select the text and do the same again.
The toolbar shows the result before you send, and you can stack underline with bold or italics on the same words.
Slack underline shortcut
| Platform | Underline shortcut |
|---|---|
| Mac | Cmd+U |
| Windows and Linux | Not in Slack's shortcut list; use the toolbar |
| Typed marker | None |
Slack's keyboard shortcuts page lists Underline selected text: Cmd+U in its Mac table. Its Windows and Linux table lists bold (Ctrl+B), italics (Ctrl+I) and strikethrough (Ctrl+Shift+X), with no underline entry, so the toolbar button is the documented way there. All formatting shortcuts are in Slack keyboard shortcuts.
Where underline does not work in Slack
Never appear "away" on Slack again
Cloud-based. No downloads. Works 24/7 even when your laptop is off.
mrkdwn text list *bold*, _italic_ and ~strike~, and no underline syntax._text_ is italic in Slack. Two underscores, __text__, do not make underline either.If a message you typed shows underscores instead of formatting, see Slack markdown not working. To preview what a bot message will look like, paste it into the Slack message formatter.
What to use instead of underline
Where underline is not available, bold is the usual way to stress a word, italics suit titles and terms, and inline code suits names and values. Some sites generate "underlined" text from Unicode combining characters (U+0332 after each letter). It shows a line in many fonts, but screen readers read the extra characters and a search for the plain word may not find it. You can see what those characters are with a short script:
text = "deadline"
underlined = "".join(ch + "\u0332" for ch in text)
print(underlined)
print(len(text), len(underlined))It prints the word with a line under it and the lengths 8 16: every letter now carries a second, hidden character. That is why we do not recommend it for work messages.
FAQ
Does Slack have underline?
Yes, in the message box: select text and click Underline in the formatting toolbar, or press Cmd+U on a Mac.
What is the underline shortcut in Slack?
Cmd+U on a Mac. Slack's shortcut list has no underline entry for Windows and Linux; use the toolbar button.
How do I underline in a Slack message sent by a bot?
You cannot with mrkdwn or the markdown block; neither has an underline syntax. Use bold or italics.
Why does _text_ not underline in Slack?
Underscores make italics in Slack. Underline has no typed marker, only the toolbar button and Cmd+U.
Can I underline in Slack on my phone?
Slack's help lists no underline steps for mobile. Type the message on desktop if the underline matters, or use bold.
Stop Jiggling Your Mouse.
Join hundreds of remote workers who never worry about their Slack status. Set it up once, stay green forever.
Related Articles
Slack Status for a Doctor Appointment: 24 Statuses and Emoji
A Slack status for a doctor appointment says you are out and when you are back, such as 🏥 'At an appointment, back at 2 PM.' You do not have to say what kind. 24 statuses for doctor, dentist and other appointments, the emoji codes, and how to schedule the status so it clears by itself.
Slack Status for Limited Availability: 30 Statuses to Copy
A Slack status for limited availability says you are around but slow, until when, and how to reach you if it is urgent, such as ⏳ 'Limited availability today, replies after 3 PM. Urgent: @mention me.' 30 statuses for busy days, slow replies and catching up, the emoji to use, and when to pause notifications too.
Slack Emoji for Thank You (and You're Welcome)
The usual Slack emoji for thank you are 🙏 :pray:, 🙌 :raised_hands: and ❤️ :heart:. For you're welcome, 😊 :blush: or 🤗 :hugging_face:. What each one says, which ones read wrong, and custom :ty:, :np: and :welcome: emoji your team can add in a minute.