slack-debloat

What is Slack Debloat?

Slack Debloat is a free, open-source tool that de-bloats the native Slack desktop app on macOS using your own CSS and JS — similar to running uBlock Origin and Tampermonkey, but for the desktop app instead of a browser. Since Slack's macOS app is built on Electron (a Chromium renderer for the same web app you use in a browser), Slack Debloat launches Slack with its Chrome DevTools Protocol port open on localhost and runs a tiny, zero-dependency injector that pushes a custom.css and custom.js into every Slack window — live-reapplying within about a second whenever you save changes.

Key Features

• No patched app: Slack.app itself is never modified, so Gatekeeper and Keychain stay intact and Slack updates normally.
• Built-in toggles via config.json: flip simple boolean options to hide the Slackbot DM row, Threads/Huddles/Drafts/Directory rows, the Activity/Later/Files/Tools tabs, the huddle button, the Slackbot AI button, and in-channel upsell banners — or make the Threads row bigger.
• Custom CSS/JS for anything else: edit custom.css or custom.js directly for changes not covered by the built-in catalog, with the same near-instant live reload.
• Auto-reflow: hidden sidebar rows collapse cleanly instead of leaving blank slots.
• DevTools access: open localhost:9222 in Chrome to inspect the running Slack app and find your own selectors.
• Simple install: a shell script seeds your config files, installs a login LaunchAgent, and builds a "Slack Debloat.app" you use in place of the regular Slack icon.

Who It's For

Slack Debloat is built for macOS users who run the native Slack desktop app and want to trim distracting UI elements — Slackbot messages, huddle prompts, promotional banners, and sidebar sections they never use — without waiting on Slack to add native customization options. It requires macOS, the Slack desktop app installed in /Applications, and Node.js 22 or later.

How It Works

A Dock-icon wrapper app launches Slack with --remote-debugging-port=9222 (bound to localhost only), while a LaunchAgent keeps an injector script running in the background. The injector polls that debugging port, attaches to every Slack window over the Chrome DevTools Protocol, and injects your custom CSS and JS — reapplying automatically on every file save and every time Slack re-renders its UI.