The counterintuitive truth
Most people assume the dedicated desktop app must be more optimized than a browser tab. For Slack, the opposite is often true. Slack's desktop app is built on Electron — which is itself a bundled copy of the Chromium browser. So either way, you're running Chromium. The question is just whether it's shared with your browser or running as a second, separate copy.
When you use Slack in Chrome or Firefox, the tab shares the browser process that's already running. Slack doesn't add a second Chromium to your system — it just adds a tab to the one that's already there.
RAM usage: the numbers
These are typical figures for a single Slack workspace after 30 minutes of light use. Your actual numbers depend on channel count, workspace size, and how long Slack has been running.
| Client | Approx. RAM | Idle CPU |
|---|---|---|
| Slack desktop app | 400–700 MB | 1–5% |
| Slack in Chrome | 150–250 MB | <1% |
| Slack in Firefox | 120–200 MB | <1% |
| msga (native client) | 60–80 MB | ~0% |
What you lose with the browser
The browser approach has real tradeoffs that matter depending on how you use Slack:
- No system tray icon. You can't see an unread badge in the taskbar or notification area without the app open.
- Less reliable notifications. Browser notifications require the tab to be open and the browser in focus. The desktop app handles notifications more dependably, especially when your computer is locked.
- "Open in Slack" links won't work. Links using the
slack://protocol — common in third-party tools — won't open in the browser tab. - Some keyboard shortcuts conflict. The browser captures certain key combinations before Slack can handle them.
The practical recommendation
For a secondary workspace you check a few times a day, the browser is the clear choice. The memory savings are 200–400 MB and the tradeoffs don't matter much.
For your primary workspace where you need fast notifications and deep-link handling, the browser tradeoff may not be worth it — but a native client is. msga gives you the desktop app experience (system tray, reliable notifications, slack:// links) without the Electron memory overhead. Same workspace, 60–80 MB instead of 400–700 MB.