Slack Zoom In and Out: Shortcuts, Limits and the Small Text Fix

To zoom in on Slack and make the text bigger, press Cmd and + on a Mac or Ctrl and + on Windows and Linux. To zoom out, press Cmd and - or Ctrl and -, and Cmd and 0 or Ctrl and 0 puts Slack back at normal size. In the desktop app each press is one step of 20%: five steps in take you to 249%, three steps out to 58%, and then the keys stop working. We read those limits from the code of Slack 4.52.182 on 2 November 2026. If Slack text suddenly looks small, an accidental Cmd and - is the usual cause, and Cmd and 0 fixes it. On iPhone and Android, Slack has no text size setting of its own; it follows the font size you set on the phone. None of this changes what your coworkers see.

The free Markdown to Slack converter shows how bold, lists and code look in Slack before you post.

Make Slack text bigger or smaller, by device

On some keyboards the + key needs Shift, so Cmd+Shift+= does the same as Cmd and +. Cmd+0 or Ctrl+0 puts the desktop app back at its normal size.

How far Slack zooms in and out

Slack's help center does not say how far the shortcuts go, so we searched the desktop app's own code, the app.asar file inside Slack.app, with this script:

import re, plistlib
data = open("/Applications/Slack.app/Contents/Resources/app.asar", "rb").read()
print("Slack", plistlib.load(open("/Applications/Slack.app/Contents/Info.plist", "rb"))["CFBundleShortVersionString"])
for m in sorted(set(re.findall(rb"case \w+\.yy\.(ZOOM_IN|ZOOM_OUT|RESET_ZOOM):return \w+\(\w,(\w\.zoomLevel[+-]1|0)\)", data))):
    print(m[0].decode(), "->", m[1].decode())
print("limits:", sorted(set(re.findall(rb"zoomLevel:\w+\(\w,(-?\d+),(-?\d+)\)", data))))
for level in range(-3, 6):
    print(f"level {level:>2}: {1.2 ** level:.0%}")

On our Mac on 2 November 2026 it printed:

Slack 4.52.182
RESET_ZOOM -> 0
ZOOM_IN -> e.zoomLevel+1
ZOOM_OUT -> e.zoomLevel-1
limits: [(b'-3', b'5')]
level -3: 58%
level -2: 69%
level -1: 83%
level  0: 100%
level  1: 120%
level  2: 144%
level  3: 173%
level  4: 207%
level  5: 249%

Each Cmd and + adds 1 to the zoom level, each Cmd and - takes 1 away, and Cmd and 0 sets it to 0. The settings code keeps the level between -3 and 5. Slack runs on Electron, which turns a zoom level into a size of 1.2 to the power of the level, so the last lines are the sizes you get:

If 249% is still too small, raise the size for the whole computer instead: Displays in macOS System Settings, or Display, Scale in Windows Settings. Slack follows both.

Set a zoom level in Slack preferences

Slack's help center gives these steps for the desktop app:

• Click your profile picture in the sidebar.
• Select Preferences.
• Click Accessibility.
• Under Zoom, select your zoom level.

The zoom setting scales everything in Slack: messages, the sidebar, names and buttons. It is only in the desktop app. We opened Preferences, Accessibility in Slack's web app on 3 October 2026, and it has display, alt text, keyboard and screen reader options but no Zoom:



In a browser, use the keyboard shortcut instead. It changes the browser's own zoom for that site.

The desktop app keeps one zoom level for the whole app, not one per workspace. On our Mac it is stored in Slack's own settings file (we read it with Slack 4.52.171 on 3 October and again with 4.52.182 on 2 November 2026):

$ python3 -c "import json,os; print(json.load(open(os.path.expanduser('~/Library/Application Support/Slack/storage/root-state.json')))['settings']['zoomLevel'])"
0

0 is the normal size. If Slack looks too big or too small in every workspace at once, this is the value that changed, and Cmd+0 or Ctrl+0 sets it back.

If the text is fine but the layout feels cramped or too spread out, try the message theme under Preferences, Messages & media. Compact fits more messages on the screen and hides profile photos; Clean is the default.

Change the font in Slack

Slack also lets you pick a different font. On desktop, click your profile picture, choose Preferences, then Appearance, and choose an option under Font. Slack says this works on desktop and in the browser, for Latin-based languages, and you set it for each workspace you are in. It changes the typeface, not the size; for size, use zoom. The same Appearance page holds Color Mode (Light, Dark or System); our Slack dark mode test shows which custom emoji vanish in each. The 10 fonts in that menu, and which font Slack uses by default, are in what font Slack uses.

Slack font size on iPhone and Android

The Slack mobile apps do not have a zoom setting. Slack's help center says the app matches the font size in your device settings:

• iPhone and iPad: Settings, Display & Brightness, Text Size, and drag the slider. For sizes beyond the slider, go to Settings, Accessibility, Display & Text Size, Larger Text.

• Android: Settings, Display, Font size. The name can differ by phone maker; search Settings for "font size".

Close and reopen Slack if the text does not change right away. This changes the text size in every app on the phone, not only Slack.

Can you change the font size of a Slack message?

No. There is no font size button in the Slack message field, and markdown headings with a # do not work in messages. Everyone reads your message at the size they chose. To make a line stand out anyway:

• Bold a short first line, like a title, then write the rest below it. Select the text and press Cmd+B or Ctrl+B.

• Use a canvas. Slack canvases support real headings, so a long update with sections reads better there. See Slack canvas vs lists.

• In a bot or workflow message, use a header block. Block Kit's header block shows a heavier title line:

{
  "blocks": [
    { "type": "header", "text": { "type": "plain_text", "text": "Release 2.4 is live" } },
    { "type": "section", "text": { "type": "mrkdwn", "text": "Dark mode, faster search, and 12 bug fixes." } }
  ]
}

We posted that message to ourselves on 3 October 2026, together with a normal message that starts with #, then deleted both:

In Slack's web app the header did not come out bigger. Its capital letters measured the same 21 pixels tall in our screenshot as the bold phrase below it, and the page styles both at 15px, the header at weight 900 and bold text at 700. The # line stayed plain text. So a header block makes a title heavier, not larger. The header text must be plain_text, so no bold or links inside it. To convert a markdown document with # headings into something Slack shows well, use our Markdown to Slack converter; it turns headings into bold lines.

Emoji follow a different rule: an emoji sent with no text shows large. See how to make Slack emoji bigger.

Slack text too small or too big after an update

• The zoom level changed. Pressing Cmd and - by accident is common. Press Cmd+0 (Ctrl+0) or check Preferences, Accessibility, Zoom.

• A new monitor or display scaling. On Windows, Slack follows Settings, System, Display, Scale. On a Mac, check System Settings, Displays.

• Browser zoom. In a browser, the zoom is per site. Reset it in the browser's menu.

• Phone text size. On mobile, check the device text size above.

More shortcuts, including the formatting keys, are in our Slack keyboard shortcuts guide.

FAQ

How do I make Slack text bigger? Press Cmd and + on a Mac or Ctrl and + on Windows and Linux, or set Zoom in Preferences, Accessibility in the desktop app.

How do I zoom out in Slack? Press Cmd and - or Ctrl and -. Three presses is the smallest Slack goes, 58%. Cmd+0 or Ctrl+0 resets the size.

Why can't I find the Zoom setting in Slack? It is only in the desktop app. Slack in a browser has no Zoom option under Accessibility, so use the keyboard shortcut.

How do I change the font size in the Slack app on my phone? Change the text size in your phone's settings. Slack follows it.