Signing in on a Mac you share with someone else

WhatsApp on macOS comes in two forms: the WhatsApp app for Mac, downloaded from WhatsApp's site or the App Store, and WhatsApp Web in a browser. Both are linked devices. They run off the WhatsApp account on a phone, and neither has its own phone number. On October 18, 2026, the WhatsApp download page said the Mac app "Requires macOS 12.1 or newer." That covers installing it. Things get harder on a Mac used by more than one person, such as a family iMac, a front desk machine, or a studio laptop people take turns on. On that day, WhatsApp's own help center said app lock was not yet available in the Mac app, and the Mac app can hold only one account. The rest of this guide covers what those limits mean on a shared Mac and four ways to keep each person's messages apart.

The two ways to run WhatsApp on a Mac

WhatsApp's help page About WhatsApp for desktops describes the Mac app as supported on macOS 12.1 and newer. It lists voice and video calls with up to 32 people, screen sharing, call links, access to up to three years of message history, and notifications that keep arriving even when the phone is offline. The app can be downloaded from the WhatsApp Download page or the Apple App Store.

One help page is out of step. How to download WhatsApp Desktop, checked the same day, still says the desktop app is available for macOS 11 or later. The download page and the About page both say 12.1, so go by 12.1. A Mac on Big Sur should use WhatsApp Web instead.

WhatsApp Web runs at web.whatsapp.com in a supported browser. It needs nothing installed, and it is the version that matters most on a shared Mac, for reasons covered below.

Both versions are set up the same way. According to the help page on linking devices, the phone acts as the primary device and can link up to four other devices. On the phone, open Linked devices, then Link a device, confirm with the phone's biometrics or PIN, and scan the QR code shown on the Mac. The page also says the primary phone has to open WhatsApp at least every 14 days, or the linked devices disconnect.

	WhatsApp for Mac	WhatsApp Web
Install	WhatsApp download page or App Store	None, runs in a browser
macOS	12.1 or newer per the download page	Any Mac with a supported browser
Calls	Voice and video, up to 32 people	The download page offers calling as a reason to get the app
App lock	Not yet available on Mac, per WhatsApp's help page	Available, password based
Accounts per install	One	One per browser session

What the next person at the keyboard can see

Once WhatsApp is linked on a shared Mac, it stays signed in. Closing the window does not sign it out, and neither does quitting the app or restarting the Mac. Whoever opens it next lands in the same chats, with the same media and the same ability to send messages as the account owner.

There is more to worry about than the chat list:

• Notifications. Message previews appear on screen for anyone sitting nearby, whether WhatsApp is open or not.
• Downloads. Photos and documents saved from a chat go to the Downloads folder of the macOS account, and every app and every person on that login can open them.
• Calls. The Mac app can receive call notifications even when it is closed, per WhatsApp's About page, so a call for one person rings for whoever is at the desk.
• Sending. Anyone at the keyboard can send a message as the account owner, and the other side cannot tell who typed it.

Logging out removes all of this, but it means scanning a QR code every time. WhatsApp's How to unlink a device page gives two ways: on the phone, open Linked devices, tap the Mac, and tap Log out. Or, on the Mac, open WhatsApp Settings, then Log out, then Log out. The phone method is the one to remember. It works after the person has already left the Mac, which is when it usually comes up.

Locks: what exists on Mac on October 18, 2026

WhatsApp has two lock features, and the Mac app does not support either one as a full answer.

App lock. The page How to use app lock, with the Mac tab selected, said in full: "App lock is not yet available for WhatsApp on Mac." The general security tips page mentions a password for Mac too, but the specific instructions page is clear that the Mac app does not have it yet.

WhatsApp Web does have it. With the Web tab selected, the same page gives these steps: click Settings, then Privacy, then App lock, select App lock, and enter a password. The password must be 6 to 128 characters and may contain letters, numbers, and common punctuation. The lock can turn on after 1 minute, 15 minutes, 1 hour, or 8 hours of inactivity. While it is locked, message contents stay hidden and notifications do not appear. To lock it right away on a Mac, press Cmd+Ctrl+L.

Chat lock. This moves selected chats into a Locked Chats folder behind extra authentication. It protects specific conversations, not the whole account, and the other chats stay open.

So on a shared Mac, the WhatsApp Web lock is currently the only built in lock with a timer that covers the whole account. That is the main reason the browser version can be the better choice on a shared machine, even though the Mac app has better calling.

Two people, two WhatsApp accounts, one Mac

Phones can now hold two WhatsApp accounts. The help page How to switch accounts on WhatsApp explains how, then adds a note that matters here: "This feature is not available on linked devices. Multiple accounts are currently only supported on mobile devices."

On a Mac, that means:

• One install of WhatsApp for Mac links to one account. A second person has to unlink the first and scan their own QR code, which signs the first person out.
• One browser session of WhatsApp Web also holds one account. Opening web.whatsapp.com in a new tab of the same browser opens the same session.
• To keep two accounts linked at the same time, each one needs its own separate place to store its session: a second macOS user account, a second browser profile, or a separate app with its own storage.

That last point is the key. On a shared Mac, signing in correctly mostly comes down to giving each account its own separate storage.

The strongest separation: a macOS account for each person

Apple's guide Change Users & Groups settings on Mac puts it directly: if a Mac has multiple users, set up an account for each person "so each can personalize settings and options without affecting other users." Accounts are added in System Settings, under Users & Groups.

The guide defines the account types. An administrator can add and manage users, install apps, and change settings. A standard user can install apps and change their own settings, but cannot add other users or change other users' settings. A guest account is for occasional use, with no access to other users' files or settings.

With a standard account per person, WhatsApp separation is complete. Each account has its own home folder, Downloads folder, browsers, Notification settings, and its own WhatsApp app link. Two people can each have WhatsApp for Mac linked to their own phone, and neither can see the other's.

Two cautions from the same guide. Automatic login lets anyone use the Mac just by restarting it, so make sure it does not log in an administrator automatically. When FileVault is on, automatic login is disabled anyway. And two administrator accounts are not truly separated from each other, so the second person should get a standard account.

This option does not fit a machine that cannot be logged out, like a reception display or a recorder that runs all day, or a managed work Mac where adding users is blocked. In those cases, the separation has to happen inside one macOS login.

Separation inside one login

Three options work without a second macOS account.

Browser profiles. A second Chrome profile, or a Safari profile, keeps its own cookies, so each profile can hold a different WhatsApp Web session. The downside is that both look like the same browser. A message for one person can be read in the wrong window, and quitting the browser closes both.

Safari web apps. On macOS Sonoma 14 or later, Apple's article Use Safari web apps on Mac explains how to open web.whatsapp.com and choose File, then Add to Dock. Apple says the web app shares no browsing history, cookies, website data, or settings with Safari. Each web app gets its own Dock icon and name, and its own entry under System Settings, Notifications. One person's WhatsApp can then be a separate app, with its own app lock set through WhatsApp Web. Apple's article adds one detail about notifications: answer the website's notification request inside the web app, not in Safari. Once that is done, the unread count appears as a red badge on that web app's Dock icon, and the app is listed under System Settings, Notifications by its own name. That makes it possible to hide previews for one person's WhatsApp without affecting anyone else's.

A dedicated app per person. A tool that turns a website into a standalone Mac app does the same thing with a Chromium browser. The tool from the publisher of this site documents the relevant settings on its Guide page. Each app gets its own browser profile automatically. An Incognito Mode setting launches the app in private mode, with the session cleared every time the app closes. On a shared Mac, that means one person's WhatsApp signs itself out when they quit. Notifications are off by default and can be turned on per app. WhatsApp is one of the built in presets listed on the Supported services page, so the URL, icon, and name are filled in automatically. The free plan covers 3 apps, and Pro is a one time $24.99.

All three options run WhatsApp Web, so they share its features and limits. That includes the password app lock, which works in each of them.

Pick the separation that matches how the Mac is shared

If each person has their own macOS account, install WhatsApp for Mac in each account and stop there. If the Mac stays on one login, use WhatsApp Web with app lock turned on, in its own window for each person, through a Safari web app or Kagemusha with Incognito Mode for anyone who should be signed out the moment they quit. In every case, show each person how to log out the Mac from their phone under Linked devices.