How to Clear Slack's Cache on Mac (and Reclaim a Couple of Gigs)

Slack ate 2.3GB of my MacBook last month before I noticed. Not the app itself — the cache. After a year of joining channels, scrolling history, and previewing files, Slack’s local cache balloons in a way that’s almost invisible until you go looking for it.

If your Mac is running low on space and Slack is one of your daily drivers, this is one of the easier wins. Here’s exactly where Slack hides its cache on macOS Sonoma and Sequoia, what’s safe to nuke, and what’ll come back the moment you reload.

Where Slack stores cache on macOS

Slack is an Electron app, which means it caches like a browser. Everything lives under ~/Library/Application Support/Slack/. The folders that actually matter:

• ~/Library/Application Support/Slack/Cache — HTTP cache, the big one
• ~/Library/Application Support/Slack/Code Cache — compiled JavaScript
• ~/Library/Application Support/Slack/GPUCache — GPU shader cache
• ~/Library/Application Support/Slack/Service Worker/CacheStorage — message and file fragments
• ~/Library/Application Support/Slack/IndexedDB — channel state
• ~/Library/Application Support/Slack/logs — diagnostic logs (often hundreds of MB)

There’s also a smaller bucket at ~/Library/Caches/com.tinyspeck.slackmacgap — less important, but worth grabbing while you’re there.

Quick way: clear cache from inside Slack

Slack ships its own cache reset, but it’s buried.

1. Open Slack on your Mac.
2. From the menu bar, click Help → Troubleshooting → Clear Cache and Restart.
3. Slack quits, wipes its in-app cache, and reopens.

That’s the polite version. It clears the HTTP cache and forces a fresh data sync, but it leaves logs, IndexedDB, and a few other folders alone. On a heavy account, you’ll get back maybe 500MB to 1GB.

Skip the manual huntSweep clears every cache across every app in one pass — Slack, Spotify, Discord, browsers, and the rest. Download Sweep free →

The thorough way: clear Slack’s full cache manually

If you want every byte back, you need to quit Slack first and clear the folders yourself.

1. Quit Slack completely. Cmd+Q from inside the app, then verify it’s gone from Activity Monitor.
2. Open Finder, hit Cmd+Shift+G, and paste ~/Library/Application Support/Slack/.
3. Inside that folder, drag these to the Trash: Cache, Code Cache, GPUCache, Service Worker, logs.
4. Empty the Trash.
5. Relaunch Slack and sign back in if asked.

Slack will rebuild what it needs on first launch. Channels reload from the server, message history streams back in as you scroll. You don’t lose anything except disk space.

What about IndexedDB?

The IndexedDB folder is where Slack caches channel content for offline scrolling. On a heavy workspace it can grow past 1GB on its own. Deleting it forces Slack to refetch everything, which is fine on a fast connection but might take a minute on the first load.

If you’re not sure, leave it. The Cache and Service Worker folders together usually account for the majority of bloat anyway.

Why Slack’s cache grows so much

A few reasons it gets out of hand:

• File previews stick around. Every PDF, image, and video preview gets cached locally for fast reload.
• Code cache compounds. Each Slack version writes new compiled JS without always cleaning the old one.
• Logs aren’t capped tightly. If you’ve ever had Slack crash, the diagnostic logs can be hundreds of MB on their own.
• Multiple workspaces multiply storage. Each workspace you’re signed into gets its own slice of cache.

If you’ve been on Slack for a year on the same Mac and never cleared it, expect 1.5–3GB sitting in there.

Doing this for every chat app gets old

Slack isn’t unique. Discord caches in ~/Library/Application Support/discord/Cache. Microsoft Teams parks data in ~/Library/Containers/com.microsoft.teams2/. Zoom dumps recordings and chat caches across multiple folders. Each one needs its own treatment.

If you’re cleaning Slack, you probably need to clean a half-dozen other apps too. Doing it manually across all of them is a 30-minute project that returns hours later as the caches refill.

Clear caches across every app at onceSweep does what 20 manual cache clears do — in 30 seconds. Free for macOS →

What Slack will look like after the clear

When you reopen Slack post-cleanup, expect:

• A 5–10 second delay on first launch as it rebuilds the workspace state
• Older channels showing “Loading messages…” until you scroll up
• File previews regenerating the next time you click a thread
• Read/unread states preserved (those live on Slack’s server, not your Mac)

Nothing is permanently lost. You’re not signing back in, not losing DMs, not breaking notifications. You’re just deleting a copy of data that Slack can refetch.

How often should you do this?

For most people, once a quarter is plenty. If you work in 10+ active channels with heavy file sharing, every couple months. If you only use Slack lightly, once a year is fine — the cache won’t get massive without volume.

The signs it’s time:

• Slack feels sluggish on launch
• Search results return slowly
• Your Mac’s storage is cramped and Slack is in the top 5 in About This Mac → Storage → Manage
• The Slack folder in ~/Library/Application Support/ is over 2GB

A faster option

Manual cache clearing works. It’s free. It’s also tedious if you have to do it for Slack, then Discord, then Chrome, then Spotify, then whatever else lives on your Mac.

Sweep is built for exactly this. It scans every app’s cache directory in ~/Library and the rest of the usual hiding spots, shows you what’s safe to remove and how much space you’ll get back, then clears it in one click. You see the list before anything happens — nothing gets deleted without your sign-off.

It handles Slack, every other Electron app, every browser, every Mac App Store install, and the system caches Apple keeps in places most people don’t know exist. Free download, paid plans for ongoing maintenance.

Bottom line

Slack’s cache on a Mac grows to 1.5–3GB for most regular users. You can clear it from the Help menu (quick, partial), or by quitting Slack and emptying the cache folders manually (thorough, takes 2 minutes). Both work. Both are worth doing every few months if storage matters to you.

If you’ve got a dozen other apps in the same situation — and you probably do — that’s where automating the whole thing starts to make sense.