MultiWA — several WhatsApp accounts, one window

What it does

MultiWA is a shell around WhatsApp Web. It adds the things a browser tab cannot give you and changes nothing about WhatsApp itself.

One tab per account: Each tab is its own WhatsApp Web session with separate cookies and storage. Scan the QR code once per tab; every account stays signed in after you quit and reopen.
Tabs you can shape: Drag to reorder, double-click to rename, pick a colour. Unread counts sit on each tab and the total shows on the Dock or taskbar icon.
Two accounts side by side: Right-click a tab and choose Show in right pane, or press ⌘\. Drag the divider to give either side more room.
Several windows: Move a tab to its own window and put it on another screen. Close that window and the tab comes back.
Everything WhatsApp Web can do: Voice notes, voice and video calls, notifications, file attachments and pasting images all work as in the browser. Downloads land in your Downloads folder.
Keyboard first: ⌘1–9 switch tabs, ⌃Tab cycles, ⌘T adds an account, ⌘R reloads one. On Windows, Ctrl instead of ⌘.

How it works

Add a tab
Click +. A fresh, empty WhatsApp Web opens in the new tab, with its own session.
Scan the code
On your phone, open WhatsApp → Linked devices → Link a device, and scan. That account is now linked to this tab only.
Keep working
Repeat for every account. Switching tabs is instant; nothing reloads. Closing a tab removes that account from this computer, after asking you.

What MultiWA never does

Never reads your messages. The only thing it reads from WhatsApp Web is the window title, to show the unread count. It does not touch the page's content.
Never sends data anywhere. There is no MultiWA server. The app talks to web.whatsapp.com and, for updates, to GitHub. Nothing else.
Never collects analytics. No usage statistics, no crash reporting, no identifiers. A local diagnostics log stays on your disk and holds no chat content.
Never gives WhatsApp a way into your computer. WhatsApp Web runs in a sandboxed view with no bridge to the system. It can ask for the microphone, camera, notifications and clipboard. Nothing else is granted.
Never follows links away. The app only navigates inside whatsapp.com. Any other link opens in your normal browser.
Never keeps what you remove. Removing an account wipes its session folder from this computer. Your phone is not affected.

All of this is enforced in code you can read: the navigation allow-list, the permission policy and the sandboxed view settings live in src/main/security, and a test suite checks that the WhatsApp view never gets a bridge. Details in SECURITY.md.

Download

macOS

Signed and notarized. Pick the Apple silicon or Intel disk image, drag MultiWA to Applications. Updates install themselves.

Get the latest release

Windows

Per-user installer, no admin rights needed. The installer is not code-signed yet, so SmartScreen will ask once: choose More info, then Run anyway.