Opening Chrome DevTools Console in Slack

October 9, 2025 • Development, Debugging

Slack is built on Electron, which means you can open Chrome DevTools inside it. Useful for monitoring API requests, debugging integrations, or setting breakpoints in the minified source.

The Process

Launch Slack from terminal with the developer menu enabled:

SLACK_DEVELOPER_MENU=true /Applications/Slack.app/Contents/MacOS/Slack

This adds a new menu option: View → Developer → Enable Main Process Inspector

Click that to start the debugger on port 9229.

Connecting DevTools

Open Chrome and go to chrome://inspect/#devices. You'll see an Electron target:

localhost:9229 (v22.19.0)
trace
electron/js2c/browser_init
file:///

Click inspect to open DevTools for the main process.

Now paste this into the console to open DevTools inside Slack itself:

const { BrowserWindow } = require('electron')
BrowserWindow.getAllWindows()[0].webContents.toggleDevTools()

DevTools opens inside Slack with full access to Network tab, Console, and Sources.

Multiple Workspaces

If you have multiple workspaces open, this opens DevTools on all of them:

const { BrowserWindow } = require('electron')
BrowserWindow.getAllWindows().forEach(w => w.webContents.toggleDevTools())

Debugging Other Node Apps

Most Node.js apps can open a debug port for inspection. For example, to debug Claude Code:

kill -USR1 $(pgrep -f claude)

Then connect via chrome://inspect/#devices to view cli.js, set breakpoints, and inspect the running process.