Slack is a popular team messaging and collaboration application that supports a subset of the Markdown syntax. Different parts of the interface provide different levels of Markdown support.
Messages
Slack’s message interface is the one people use most. In its support documentation, the company claims that they’ve “chosen not to support” Markdown in the message interface, but that’s not entirely true. Support for some basic syntax is provided, although support for many elements is notably absent.
Slack Markdown Support in Messages
The Slack message interface provides support for the following the Markdown elements.
| Element | Support | Notes |
|---|---|---|
| Headings | No | |
| Paragraphs | No | |
| Line Breaks | No | The Markdown syntax is not supported, but you can press the Shift and Return keys to go to the next line. |
| Bold | No | The Markdown syntax is not supported, but you can add bold styling with single asterisks, which is the standard Markdown syntax for italic. Very confusing! |
| Italic | Partial | Only underscores are supported. |
| Blockquotes | Yes | |
| Ordered Lists | Yes | |
| Unordered Lists | Yes | |
| Code | Partial | Code blocks are not supported. |
| Horizontal Rules | No | |
| Links | No | |
| Images | No | The Markdown syntax is not supported, but you can drag and drop images to share them. |
| Tables | No | |
| Fenced Code Blocks | Yes | Syntax highlighting is not supported. |
| Footnotes | No | |
| Heading IDs | No | |
| Definition Lists | No | |
| Strikethrough | Partial | Use only one tilde symbol before and after the phrase. |
| Task Lists | No | |
| Automatic URL Linking | Yes | |
| Disabling Automatic URL Linking | Yes | |
| HTML | No |
Posts
The Slack post interface is editor that allows you to create a document for sharing in Slack. This is a live editor, which means you will see the actual formatting immediately after you type Markdown formatted text. For example, if you type _test_, the underscores will disappear and you’ll see the word “test” in italics.
To create a post, click the paperclip icon and select Post from the Create new menu, as shown below.
Slack Markdown Support in Posts
The Slack post interface provides support for the following Markdown elements.
| Element | Support | Notes |
|---|---|---|
| Headings | Partial | Only heading levels one and two are supported. Only number signs are supported. |
| Paragraphs | Yes | |
| Line Breaks | No | |
| Bold | No | The Markdown syntax is not supported, but you can add bold styling with single asterisks, which is the standard Markdown syntax for italic. Very confusing! |
| Italic | Partial | Only underscores are supported. |
| Blockquotes | Yes | |
| Ordered Lists | Yes | |
| Unordered Lists | Yes | |
| Code | Yes | |
| Horizontal Rules | No | |
| Links | No | |
| Images | No | |
| Tables | No | |
| Fenced Code Blocks | Yes | Syntax highlighting is not supported. |
| Footnotes | No | |
| Heading IDs | No | |
| Definition Lists | No | |
| Strikethrough | Partial | Use only one tilde symbol before and after the phrase. |
| Task Lists | No | |
| Automatic URL Linking | Yes | |
| Disabling Automatic URL Linking | Yes | |
| HTML | No |
See Also
- Formatting Slack messages in the interface
- Formatting Slack posts in the interface
- API documentation for formatting Slack messages
- slack_markdown ruby gem
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