DevTools

Using DevTools

When running your Worker locally using the Wrangler CLI (wrangler dev) or using Vite with the Cloudflare Vite plugin, you automatically have access to Cloudflare's implementation of Chrome DevTools.

You can use Chrome DevTools to:

• View logs directly in the Chrome console
• Debug code by setting breakpoints
• Profile CPU usage
• Observe memory usage and debug memory leaks in your code that can cause out-of-memory (OOM) errors

Opening DevTools

Wrangler

• Run your Worker locally, by running wrangler dev
• Press the D key from your terminal to open DevTools in a browser tab

Vite

• Run your Worker locally by running vite
• In a new Chrome tab, open the debug URL that shows in your console (for example, http://localhost:5173/__debug)

Dashboard editor & playground

Both the Cloudflare dashboard and the Worker's Playground include DevTools in the UI.

Related resources

• Local development - Develop your Workers and connected resources locally via Wrangler and workerd, for a fast, accurate feedback loop.