How to React to a Message in Slack: Click, Shortcut or +:emoji:

To react to a message in Slack, hover over it, click the Add reaction icon (a smiley face with a plus sign) and pick an emoji. On iPhone or Android, tap and hold the message and choose an emoji. Two faster ways react to the most recent message in the conversation: press Cmd+Shift+\ on a Mac or Ctrl+Shift+\ on Windows, or type +:eyes: (or any emoji code with a plus in front) in the message box and press Enter. Click your own reaction a second time to remove it.

We tested the +:emoji: trick on 28 September in a Slack DM. Sending +:eyes: added a 👀 reaction to the message above and posted nothing. On October 4 we also found the limit: one person can put 23 different reactions on one message. The keyboard shortcut and the phone steps come from Slack's help center.

How to react to a Slack message on desktop

• Hover over the message you want to react to. A small toolbar appears at its top right.
• Click Add reaction, the smiley face with a plus sign.
• Pick an emoji, or type a word such as tada or eyes in the search box.
• The reaction appears under the message with a count. Your own reactions are highlighted in blue; click one again to remove it.

To see who reacted, hover over a reaction. To add the same reaction someone else already added, click it; the count goes up by one.

Six ways to add a reaction in Slack

Way	How	Reacts to
Hover menu	Hover, click Add reaction, pick an emoji	Any message
One-click reactions	Hover, click one of the 3 suggested emoji (if turned on)	Any message
Keyboard shortcut	Cmd+Shift+\ (Mac) or Ctrl+Shift+\ (Windows, Linux)	The latest message
Typed +:emoji:	Send +:thumbsup: or +:eyes: in the message box	The latest message
Focused message	Move to a message with the arrow keys, press R	The focused message
Phone	Tap and hold the message, pick an emoji	Any message

Details for each:

• • One-click reactions are the three emoji Slack shows when you hover. Owners and admins set the defaults for the workspace in Tools & settings, Customize, Emoji. You can change yours in Preferences, Messages & media, Emoji: turn Show one-click reactions on messages on or off, and choose My most frequently used emoji or Custom.
• • The shortcut depends on your keyboard layout. Slack's shortcut list shows other keys in place of the backslash on other layouts, such as # or _. See Slack keyboard shortcuts for the full list.
• • +:emoji: works with any standard or custom emoji code, so +:white_check_mark: marks the last message as done. The codes are in our Slack emoji codes list.
• • The R key works after you move focus onto a message. It sits with the other one-key message actions: E to edit, T to open a thread, P to pin.

How many reactions can you add to one Slack message?

23 different emoji per person. We posted a test message to ourselves and added reactions one by one through the API. Reactions 1 to 23 went through. The 24th returned too_many_reactions, and adding 👀 a second time returned already_reacted.



Trying a 24th from the reaction menu in the app opens this dialog instead:



The cap is per person, so a busy message can show more than 23 kinds of emoji when several people react. Hovering over a reaction shows who added it, and on your own it reads "You (click to remove)".

Slack's built-in reaction meanings

The reaction menu has a Getting Work Done row with a tooltip on each emoji. These are Slack's own words, read from the menu on October 4, 2026:

Emoji	Slack's tooltip
✅ white check mark	Let others know this task is done
👀 eyes	Let others know you're looking into this
🙌 raised hands	Say good job to someone
🙏 pray	Show your gratitude
➕ heavy plus sign	Show you agree
👏 clap	Give a round of applause
💡 bulb	Show you think this is a good idea
🎯 dart	Let others know they're on the right track
👋 wave	Say hello
👍 thumbs up	Express your approval
🎉 tada	Celebrate great work or news
1️⃣ 2️⃣ 3️⃣	Vote for option 1, 2 or 3
📣 mega	When sharing an important message
⚪ 🔵 🔴 circles	Low, medium and high importance

How to react on iPhone and Android

Open the conversation and tap and hold the message.

Tap one of the frequently used emoji at the top of the menu, or tap Add reaction to search.

To remove your reaction, tap it under the message.

Slack's iOS note is worth knowing: the phone keyboard's emoji button inserts Apple emoji into a message, but Slack's own and custom emoji come from typing their code or from the reaction menu.

React with a custom emoji

Any custom emoji your workspace has added shows up in the reaction menu for everyone. Search it by name, or send +:its-name:. To add your own:

Make a square image. Our free Slack emoji maker turns text or a photo into an emoji, and the Slack emoji resizer shrinks a file under Slack's 128 KB limit in your browser.

Upload it from the emoji menu with Add emoji. The steps and size rules are in how to add custom emoji to Slack.

Give it a short name, such as :lgtm: or :shipit:, then react with it.

For ideas, see 40 Slack emoji ideas for work. What the common reactions mean inside a team is in what does the eyes emoji mean in Slack, and ready-made thank-you reactions are in Slack emoji for thank you.

Reply to a specific message instead

A reaction is a one-emoji answer. When you need words, pick one of these:

• Reply in a thread. Hover the message and click Reply in thread, or focus it and press T. The reply stays attached to that message.

• Quote it. Copy the message link or type > before the text you are answering. See how to quote a message in Slack.

• Forward it. Hover, click Forward, and add a note.

Add a reaction with the Slack API

Bots and scripts add reactions with the reactions.add method. It needs the reactions:write scope, the channel ID, the message timestamp (ts) and the emoji name without colons:

curl -X POST https://slack.com/api/reactions.add \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"channel": "C0123456789", "timestamp": "1727488800.123456", "name": "white_check_mark"}'

The same call from Python with the official slack_sdk package:

import os
from slack_sdk import WebClient

client = WebClient(token=os.environ["SLACK_BOT_TOKEN"])
client.reactions_add(channel="C0123456789", timestamp="1727488800.123456", name="thumbsup::skin-tone-3")

A success returns {"ok": true}. Skin tones go after the name, like thumbsup::skin-tone-3 (2 to 6); in our test skin-tone-1 and skin-tone-7 returned invalid_name, see Slack skin tone. Errors we hit in testing: already_reacted when that emoji is already there from you, and too_many_reactions on your 24th different emoji on one message. Slack's docs also list too_many_emoji for a message that has hit its total limit of different emoji. To turn a message ts into a readable time, or to build a date that shows in each reader's time zone, use our Slack timestamp tool.

FAQ

Is there a limit on reactions in Slack?

Yes. One person can add 23 different emoji to one message. Slack shows "You've reached the reaction limit" on the 24th.

Can people see who reacted to a message?

Yes. Hover over a reaction on desktop, or tap and hold it on a phone, to see the names.