By default, you can use the formatting toolbar to format your messages in Slack. If you prefer to use markup instead, you can set a preference to hide the toolbar from the message composer. If you set this preference, here’s what to expect:
Formatting will be applied to messages after you send them.
Messages that you copy and paste will appear in plain text.
Automatic formatting for bulleted, numbered, and indented lists won't be applied.
Set your message formatting preference
From your desktop, click your profile picture in the sidebar.
Select Preferences from the menu.
Select Advanced.
Under Input Options, check or uncheck the box next to Format messages with markup.
Use markup
Once you’ve set your formatting preference, you can use the following markup actions to format your messages.
Formatting
Description
Bold
Surround text with asterisks: *your text*
Italic
Surround text with underscores: _your text_
Strikethrough
Surround text with tildes: ~your text~
Code
Surround text with backticks: `your text`
Block quote
Add an angled bracket in front of text: >your text
Code block
Surround text with three backticks: ```your text```
Link
Surround text with brackets, then surround the link with parentheses: [your text](the link)
