Slack formats text using markup characters typed directly into the message box. Surround a word or phrase with asterisks for bold, underscores for italic, tildes for strikethrough, or backticks for inline code. These shortcuts work on desktop, mobile, and the web app, and your formatting appears the moment you send the message.
Quick-reference table
| Format | Syntax | Example typed | Result |
|---|
| Bold | *text* | *deadline* | deadline |
| Italic | _text_ | _please review_ | please review |
| Strikethrough | ~text~ | ~old price~ | old price |
| Inline code | `text` | `console.log()` | console.log() |
| Code block | ```text``` | ```function init()``` | (formatted block) |
| Block quote | > text | > noted | (indented quote) |
| Ordered list | 1. item | 1. First step | 1. First step |
| Bullet list | * item or - item | * Buy milk | (bulleted item) |
You can also toggle bold, italic, and strikethrough from the formatting toolbar above the message input. Click the Aa button to reveal it if it is hidden.
Bold text
Wrap your text in single asterisks: *like this*. The asterisks disappear after you send, leaving the text visually heavier.
Bold works well for deadlines, action items, or names you want a reader to notice quickly in a long thread. For a deeper look at bold formatting across platforms, see our guide on how to format bold text.
Italic text
Use underscores: _like this_. Italics are useful for titles of documents, light emphasis, or side comments where bold would feel too strong.
One thing to watch: if your text already contains underscores (common in file names or URLs), Slack may misinterpret them. In those cases, highlight the text and use the toolbar italic button instead.
Strikethrough
Surround text with tildes: ~like this~. Strikethrough shows that something has been removed or completed without deleting the original text. It is common in channels where people update task lists inline.
Inline code
Use single backticks: `like this`. The text renders in a monospace font with a subtle background highlight. Helpful for variable names, terminal commands, file paths, or any short snippet you want visually distinct from regular prose.
Code blocks
For multi-line code, use triple backticks on their own lines. The entire block renders in a monospace font with a scrollable container. Slack does not support language-specific syntax highlighting in messages, so all code blocks look the same regardless of language.
Block quotes
Start a line with > followed by a space. Everything on that line appears indented with a vertical bar on the left. This is handy for quoting someone else's message or highlighting a key sentence from a document.
To quote multiple lines, start each line with >. Slack treats consecutive quoted lines as one block.
Ordered and unordered lists
Type 1. followed by a space to start a numbered list. Each subsequent line starting with the next number continues the sequence. For bullet points, use * or - at the start of a line followed by a space.
Slack added native list support in 2023. On older mobile app versions, you may need to type the numbers or bullets manually rather than relying on auto-formatting.
Links
Slack auto-links any URL you paste. You do not need special syntax. If you paste https://example.com, it becomes a clickable link automatically.
To create a hyperlink with custom display text, highlight the text you want to link, then press Cmd+Shift+U (Mac) or Ctrl+Shift+U (Windows/Linux) and paste the URL. There is no inline Markdown-style link syntax in Slack messages.
Mentions and notifications
Type @ followed by a username to mention someone directly. Slack also supports channel-wide mentions:
@here notifies only members currently online in the channel@channel notifies every member of the channel, regardless of status@everyone works in some workspaces and notifies all members
Mentions trigger notifications, so use @channel and @everyone with care in large channels.
Emoji shortcodes
Type a colon followed by the emoji name and a closing colon: :thumbsup:, :fire:, :rocket:. Slack auto-suggests matching emoji as you type. You can also open the emoji picker with the smiley face icon or the shortcut Cmd+Shift+\ (Mac) or Ctrl+Shift+\ (Windows/Linux).
Workspace admins can upload custom emoji, which also work with the :name: shortcode syntax.
What Slack does not support
A few formatting options that people commonly look for are not available natively in Slack:
- Underline. There is no underline syntax in Slack. The platform simply does not support it in messages.
- Text color. You cannot change font color in Slack messages.
- Font changes. All messages use Slack's default typeface. There is no way to switch fonts.
- Headings or font sizes. Unlike a document editor, Slack has no heading hierarchy.
These formatting limitations apply to regular messages. Channel topics, channel descriptions, and workspace names have even fewer options.
If you need underlined text, colored text, or stylized fonts in a Slack message (for example, to make a channel topic stand out), you can generate Unicode-styled text with the Slack text formatter on BoldlyType and paste it in. Unicode formatting is purely visual and works anywhere text can be pasted.
You can nest formatting characters. For example, *_bold and italic_* renders as bold italic text. The order of the markers matters: start and end with the outermost format.
Common combinations:
*_text_* for bold italic*~text~* for bold strikethrough_~text~_ for italic strikethrough
Triple nesting (bold + italic + strikethrough) also works but gets hard to read in the message input.
Tips for readable Slack messages
Formatting is only useful if it makes messages easier to scan. A few practical habits:
- Use bold sparingly. If everything is bold, nothing stands out.
- Use code formatting for anything technical: API endpoints, error codes, file names.
- Break long updates into bullet points rather than writing dense paragraphs.
- Use block quotes when you are responding to a specific part of someone's earlier message.
For more on formatting across messaging platforms, our multi-platform formatting guide covers WhatsApp and Discord alongside Slack. And if you are looking for tools to style text for social media profiles and bios, see the roundup of free text formatting tools.
