The counterintuitive truth
Most people assume a dedicated Slack desktop client 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 existing browser or running as a second, separate copy contributing to Slack's high memory usage.
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.
Slack RAM usage: the numbers
These are typical figures for a single Slack workspace after 30 minutes of light use. Your actual Slack RAM usage will 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% |
Slack high RAM usage: why the desktop app costs more
Understanding why Slack desktop memory usage runs so high makes the table above less surprising. The official Slack desktop client ships with its own copy of Chromium baked in via Electron. That bundled browser loads alongside every workspace you open, regardless of whether Chrome or Firefox is already running on your machine. The result is two Chromium instances competing for memory rather than one.
A native Slack desktop client built without Electron — like msga, which is written in C++/Qt6 — avoids this entirely. It talks directly to Slack's APIs without embedding a browser, which is why its idle memory footprint is a fraction of the official app's.
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 substantial and the tradeoffs rarely matter in light use.
For your primary workspace where you need fast notifications and deep-link handling, the browser tradeoff may not be worth it — but a native Slack desktop client is. msga resolves Slack's high RAM usage while giving you the full desktop experience: system tray, reliable notifications, and slack:// link handling. Same workspace, 60–80 MB instead of 400–700 MB, with none of the Electron overhead.