Slack Formatting Toolbar Missing? How to Get It Back

If the formatting toolbar is missing in Slack, click the Aa button under the message field. It shows and hides the toolbar, and Slack remembers the choice, so one stray click hides it for good. If there is no Aa button at all, Format messages with markup is turned on: open Preferences, then Advanced, and under Input options uncheck it. We tested both in the Slack web app on October 4, 2026. If you clicked Don't ask again on the "Apply formatting" prompt, that is a different setting, and Cmd+Shift+F (Ctrl+Shift+F) still applies the formatting.

The free Markdown to Slack converter has its own mrkdwn toolbar, so you can also draft a formatted message there and paste it into Slack.

The three states of the Slack composer

We switched each setting in our own workspace and looked at the message field after each change.

• • Default. The toolbar sits above the text field, and the Aa button below it is highlighted.
• • After clicking Aa. The toolbar disappears and the Aa button stays, with the tooltip "Show formatting". The toolbar was still hidden after we reloaded Slack, which is why it seems to vanish on its own.
• • With Format messages with markup on. The toolbar and the Aa button are both gone. Nothing in the composer tells you why.

So the fastest check is to look for the Aa button. If you see it, click it. If you do not, go to Preferences.

Turn off Format messages with markup

• Click your profile picture, then Preferences.
• Open Advanced.
• Under Input options, uncheck Format messages with markup. Slack's own note under the box says "The text formatting toolbar won't show in the composer."


The change applies right away, with no restart. When we unchecked the box, the toolbar and the Aa button came back at once.

Why would anyone turn markup mode on? People who type formatting by hand, such as developers who like writing backticks, see the characters as they type and the formatting after sending.

If neither fix works in the desktop app, choose Help, then Troubleshooting, then Clear Cache and Restart, and install any Slack update. On iPhone and Android, tap Aa above the keyboard to show the formatting options.

What is on the Slack formatting toolbar

The toolbar we saw has 10 buttons, in this order: Bold, Italic, Underline, Strikethrough, Link, Ordered list, Bulleted list, Blockquote, Code and Code block. The shortcuts come from Slack's keyboard shortcut list; on Windows and Linux use Ctrl in place of Cmd.

Button	Shortcut, Mac	Typed markup
Bold	Cmd+B	*text*
Italic	Cmd+I	_text_
Underline	Cmd+U	none
Strikethrough	Cmd+Shift+X	~text~
Link	Cmd+Shift+U	paste a URL over selected text
Ordered list	Cmd+Shift+7	1. and a space
Bulleted list	Cmd+Shift+8	an asterisk and a space
Blockquote	Cmd+Shift+9	> text
Code	Cmd+Shift+C	one backtick on each side
Code block	Cmd+Alt+Shift+C	three backticks on each side

Select the text and click a button. You can stack several, such as bold and italic, on the same words. Each one has its own guide: bold, strikethrough, code blocks, bullet points and links.

The "Apply formatting" prompt and "Don't ask again"

When you paste text that contains markdown, such as **bold** from ChatGPT or a README, Slack shows a small prompt at the bottom of the window. It is not part of the toolbar, and it follows its own rules. We read them in the Slack web client that the Slack desktop app had cached on our Mac (cached 28 October 2026), with a script that prints the prompt's code:

first paste:       Looks like your content contains markdown. | Apply formatting | Don’t ask again
later pastes:      Apply formatting? | Apply | Don’t ask again
toast duration ms: 1e4
don't ask again:   {pref:"seen_markdown_paste_toast",value:-1}
shortcut (Mac):    "You can do this any time with <span>⌘ Shift F</span>"
shortcut (other):  "You can do this any time with <span>Ctrl Shift F</span>"
shortcut hint shown: first 3 times

What that means in practice:

Format a Slack message without the toolbar

All of these work with the toolbar hidden:

The toolbar does not appear in fields that are not messages, such as the Edit topic box, and markup has no effect inside a code block. Typed markup still works in a channel topic: in our topic test *on track* showed in bold in the channel header.

FAQ

Does hiding the toolbar change how my messages look to others?

No. It only changes your own composer. Messages you send look the same, and the shortcuts and typed markup still work.

How do I undo "Don't ask again" on Slack's Apply formatting prompt?

Slack saves that choice to your account. In the client code we read, nothing else touches that preference, so we found no setting that shows the prompt again. Use the shortcut instead: select the pasted text and press Cmd+Shift+F (Ctrl+Shift+F).