If WhatsApp Desktop feels heavier than you remember, or heavier than a messaging app seems like it should be, that's a documented, deliberate architecture change rather than something going wrong on your specific Mac.
What changed: native to Electron
WhatsApp's older Mac desktop app was built natively for macOS, using Apple's own frameworks directly. The newer version is built on Electron, which bundles a full Chromium browser engine and a Node.js runtime inside every app, so the interface can be built with web technologies (JavaScript, HTML, CSS) and shared more easily across Mac, Windows, and Linux from one codebase. This is the same trade-off Slack, Discord, Notion, and many other modern apps have made: faster development across platforms, at the cost of a heavier baseline memory footprint than a fully native equivalent.
How much heavier is it, really?
Independent write-ups comparing the two versions describe the new Electron-based WhatsApp Desktop using roughly seven times the memory of the old native app for comparable use, with reports of usage surging past 1.2GB simply from scrolling through chat history, a task that used barely any memory on the old client. For an app whose core job is displaying text messages and occasional media, that's a meaningful jump, and it's the direct, well-understood cost of the Electron architecture rather than a bug specific to WhatsApp's implementation.
Why Electron apps behave this way generally
Every Electron app effectively runs its own private copy of a Chromium browser in the background, plus a separate rendering process for the interface itself, similar to how each browser tab in Chrome gets its own process. That's why a suite of Electron apps (WhatsApp, Slack, Discord, Notion, Spotify) running simultaneously can consume memory disproportionate to how simple their individual jobs look on the surface: you're effectively running several small browsers at once, each with its own overhead, even though none of them look like a browser to you.
What genuinely helps
Quit WhatsApp Desktop when you're not expecting messages. Unlike a truly lightweight native app, WhatsApp Desktop's Electron overhead means leaving it open "just in case" costs more memory than it would for a genuinely native equivalent. If you get notifications on your phone anyway, quitting the desktop app between uses is a reasonable habit.
Avoid keeping many chat threads with heavy media open at once. Scrolling through long media-rich conversations is specifically called out as a memory-heavy action in the reports above. If you need to review old media, doing it in shorter sessions rather than scrolling extensively may keep peak usage lower.
Restart the app periodically during heavy use. As with most Electron apps, a full quit-and-reopen clears accumulated memory more thoroughly than leaving it running indefinitely, particularly after reviewing a lot of chat history in one sitting.
Is there a lighter alternative?
WhatsApp's web client (web.whatsapp.com) run in a normal browser tab has a similar underlying architecture (it's also Chromium-based when run in Chrome or Edge), so it doesn't necessarily solve the memory question, though it does mean you're managing one browser's memory rather than a separate dedicated app's. There isn't currently an official lightweight native alternative from Meta itself.
Where a memory-relief tool fits in
WhatsApp Desktop's Electron overhead is architectural, quitting the app is the direct way to reclaim that specific memory. What Shiny helps with is the broader picture when you're running WhatsApp alongside other Electron apps like Slack, Discord, or Notion, each contributing its own overhead simultaneously. Freeing memory in one click clears what's accumulated across all of them at once, which is often more useful than restarting each Electron app individually.
For the wider pattern across similar apps, see Electron apps on Mac: the growing footprint, which covers this exact architectural trade-off across several popular apps.
Why cross-platform apps keep making this trade-off anyway
It's worth understanding why WhatsApp, and so many other companies, keep choosing Electron despite the well-known memory cost, since it explains why this pattern isn't likely to reverse soon. Building and maintaining three separate native codebases (Mac, Windows, Linux) is significantly more expensive in engineering time than building one Electron app that runs everywhere with minor platform-specific adjustments. For a company the size of Meta, this is a straightforward cost trade-off: engineering hours saved building one shared codebase against the memory cost users experience running it. That calculation rarely favours going back to native once a company has made the switch, which is why once an app moves to Electron, it tends to stay there.
What this means for your Mac's overall memory budget
If you're someone who runs several messaging and productivity apps simultaneously (WhatsApp alongside Slack, Discord, Teams, and a browser with dozens of tabs), it's worth recognising that each Electron app is contributing its own baseline overhead on top of whatever it's actively doing. This adds up faster on a Mac with less RAM to begin with, which is part of why 8GB Macs in particular can feel pressured even during what looks like light everyday multitasking; the apps themselves, not any single heavy task, account for a meaningful chunk of the baseline.