iMessage on Mac lets you send encrypted messages to other Apple users through your Apple ID instead of a phone number

iMessage is Apple's encrypted messaging service built into macOS. When you turn it on, your Mac can send and receive text messages, photos, and videos to anyone with an Apple device — iPhone, iPad, or another Mac. The messages travel through Apple's servers rather than your phone carrier, and they're encrypted end-to-end, meaning Apple cannot read them.

To use iMessage on your Mac, you need an Apple ID, a Mac running a recent version of macOS, and an internet connection. The setup takes about five minutes and happens in the Messages app, which comes pre-installed on every Mac.

Key Takeaways

  • iMessage requires your Apple ID and works only when your Mac is connected to the internet.
  • You can receive messages on your Mac even if your iPhone is turned off, as long as your Mac is on.
  • Turning on iMessage does not affect your regular SMS text messages, which still use your phone number and carrier.
  • You can turn iMessage off at any time without losing your messages or affecting other Apple devices.

Open Messages and sign in with your Apple ID

Open the Messages app on your Mac. You can find it in the Applications folder or by clicking the Launchpad icon in the dock and typing "Messages". When the app opens, you should see a list of conversations on the left side and a blank message area on the right.

Go to Messages in the menu bar at the top of your screen, then click Preferences. A settings window will open. Click the Accounts tab at the top. If you see your Apple ID already listed under iMessage, you're already signed in — skip to the next section. If not, click the plus sign (+) at the bottom left of the window.

Select iMessage from the dropdown menu that appears. Enter your Apple ID email address and password, then click Sign In. macOS will verify your credentials and add iMessage to your account.

Enable iMessage in your account settings

After you sign in, you'll return to the Accounts tab. Your Apple ID should now appear in the list on the left side. Click on it to see the iMessage options for that account.

Check the box next to "Enable this account". This turns on iMessage for your Mac. You should also see a checkbox for "You can be reached for messages at" — this shows the email addresses and phone numbers where people can contact you via iMessage. Your Apple ID email is usually checked by default. You can add other email addresses or your phone number if you want people to reach you through those as well.

Close the Preferences window. iMessage is now active on your Mac.

Verify iMessage is working

Open the Messages app and start a new message. Click the plus sign (+) in the top left corner, or go to File > New Message. Type the name or phone number of someone you know who uses an Apple device. If iMessage is working, their name will appear with a blue circle next to it. If you see a green circle instead, the message will be sent as a regular SMS text through your carrier.

Send a test message to confirm it goes through. iMessage messages appear in blue bubbles in the conversation. Regular SMS messages appear in green bubbles.

What to do if iMessage won't turn on

If you see an error message when trying to sign in, make sure you're using the correct Apple ID and password. If you've forgotten your password, go to iforgot.apple.com to reset it before trying again in Messages.

Check that your Mac is connected to the internet — iMessage requires Wi-Fi or a wired connection to work. If you're on Wi-Fi, try disconnecting and reconnecting to make sure the connection is stable.

If iMessage still won't turn on, sign out and sign back in. Go to Messages > Preferences > Accounts, click your Apple ID, and click the minus sign (−) to remove it. Then click the plus sign (+) again and sign in with your Apple ID a second time. This often clears up temporary connection problems.

If you're still having trouble after these steps, restart your Mac. Shut down completely, wait 30 seconds, and turn it back on. Then open Messages and try signing in again.

How iMessage affects your other devices

When you turn on iMessage on your Mac, it automatically syncs with your iPhone and iPad if they're signed into the same Apple ID. This means you'll receive the same messages on all your devices. If someone sends you an iMessage, it will show up on your Mac, iPhone, and iPad at the same time.

You can turn iMessage on or off separately on each device without affecting the others. If you turn it off on your Mac but leave it on your iPhone, you'll only receive messages on your iPhone. Your messages are stored in iCloud if you have iCloud Messages turned on, so they'll be available on whichever device you're using.

Privacy and security with iMessage

iMessage uses end-to-end encryption, which means the messages are scrambled in a way that only you and the person you're messaging can read them. Apple cannot see the content of your messages, and neither can your internet provider or anyone else intercepting the connection.

When you send an iMessage, it's encrypted on your Mac before it leaves, travels through Apple's servers in encrypted form, and is decrypted only on the recipient's device. This is different from regular SMS text messages, which your phone carrier can see and which are not encrypted.

iMessage also shows you when the other person is typing and when they've read your message — these are called read receipts. You can turn off read receipts in Messages > Preferences > General if you don't want people to know when you've seen their messages.

Frequently Asked Questions

Can I use iMessage without an iPhone?

Yes. You can use iMessage on your Mac with just an Apple ID, even if you don't own an iPhone. Other people can reach you at the email address you set up in iMessage. However, they need to know your email address rather than your phone number to start a conversation with you.

Will turning on iMessage stop my regular text messages?

No. iMessage and SMS text messages are separate. If someone sends you a regular text to your phone number, it will still arrive as an SMS. iMessage only handles messages sent to your email address or from other Apple users.

What happens to my messages if I turn off iMessage?

Your existing messages stay in the Messages app and remain readable. Turning off iMessage just stops new messages from being sent and received through iMessage. You can turn it back on at any time and your conversation history will still be there.

Can I use iMessage on a Mac that's not connected to Wi-Fi?

No. iMessage requires an active internet connection to send and receive messages. If your Mac loses Wi-Fi, iMessage will pause until you reconnect. Regular SMS text messages sent from your iPhone don't have this limitation because they use your cellular connection.

Why do some messages show as green instead of blue?

Green bubbles mean the message was sent as a regular SMS text through your carrier instead of through iMessage. This happens when you're messaging someone without an Apple device, or when iMessage isn't available. Green messages may have a character limit and are not encrypted the same way iMessage messages are.