| Method | Description | Difficulty |
|---|---|---|
| Disable Hardware Acceleration | Prevents Slack from using the GPU, which often causes CPU spikes. | Easy |
| Clear Slack Cache | Wipes temporary files that may cause processing loops. | Easy |
| Manage Workspaces | Closing unused workspaces reduces memory and CPU load. | Moderate |
| Reinstall Slack | Ensures a clean installation of the latest version. | Moderate |
What is Slack High CPU Usage?
Slack high CPU usage occurs when the application consumes an excessive percentage of your processor’s capacity. This often leads to system lag, loud fan noise, and overall slow performance.
Since Slack is built on the Electron framework, it essentially runs as a web browser. Each workspace you join operates as an individual process, which can quickly drain system resources if not managed correctly.
Step-by-Step Solutions
1. Disable Hardware Acceleration
Hardware acceleration offloads certain tasks to your GPU. However, it is a common culprit for high CPU usage on specific hardware configurations.
To disable it, open Slack and go to File > Preferences > Advanced. Uncheck the box that says “Disable hardware acceleration.” You will need to restart Slack for this change to take effect.
2. Clear the Slack Cache
Corrupted cache files can lead to infinite loops, causing the CPU to work harder than necessary. Clearing the cache refreshes the application’s environment.
Navigate to Help > Troubleshooting > Clear Cache and Restart. If you are using Linux and need to manually clear the directory via terminal, you can target the Slack config folder:
rm -rf ~/.config/Slack/Cache/* && rm -rf ~/.config/Slack/Service\ Worker/CacheStorage/*3. Minimize Active Workspaces
Every active workspace in the Slack sidebar runs its own set of background processes. If you are signed into five different workspaces, your CPU usage can quintuple.
Right-click on workspaces you don’t use frequently and select “Sign out of [Workspace Name]” or “Close Workspace” to free up immediate resources.
4. Update Slack to the Latest Version
The Slack engineering team frequently releases patches for memory leaks and performance bugs. Using an outdated version can leave you with unoptimized code.
Check for updates by clicking your profile picture, navigating to Help, and selecting Check for Updates. On macOS, you can also use Homebrew to ensure it is updated:
brew upgrade --cask slack5. Manage Integrated Apps and Giphy
Animated GIFs and certain heavy integrations can cause spikes in CPU usage every time they render. If a specific channel is very “noisy” with media, it may slow down the entire client.
Go to Preferences > Messages & Media and disable “Show images and prints from URL” or “Automatically play GIFs” to reduce the rendering load on your processor.