Slack in a browser (Chrome or Firefox) has no such restriction. Open your browser, navigate to app.slack.com . It is slower, notifications are clunky, and you cannot drag files easily, but it works perfectly. This bypasses the Electron dependency entirely.
While High Sierra was once a stable workhorse, running it today means looking at a frustrating message in the Slack sidebar:
macOS 10.13 High Sierra was a great operating system. It brought APFS (Apple File System) to the world. But in the SaaS era, software is a perishable good. Slack didn't just "drop support" out of spite; the code literally cannot breathe the air of a system that is half a decade out of date.
Tools like dosdude1 's macOS Mojave/Catalina patchers allow unsupported Macs to run newer OSes. However, this kills graphics acceleration. Slack, ironically, becomes a stuttering mess on patched hardware.
Apple stopped issuing security patches for High Sierra in . If you are running 10.13, your machine has known unpatched vulnerabilities, including the infamous CVE-2019-8518 (a logic issue allowing malicious applications to bypass Gatekeeper).
If you see that error message, your only stable, secure path forward is either macOS 10.14 Mojave (via patcher) or the web browser. The native Mac app is gone for good. Article based on Slack’s official system requirements as of 2024 and developer analysis of Electron/Rust dependencies.
However, for the IT manager or the freelancer on a budget: Chrome on High Sierra still receives security updates (for now). Keep a pinned tab for Slack.
Here is a deep dive into why Slack killed support for macOS 10.13, the security implications, and the few remaining options for users stuck on legacy hardware. Slack follows a predictable lifecycle policy. Generally, the company supports the current major version of macOS and the previous two. When macOS Ventura (13.0) dropped, macOS 10.13 fell off the cliff.