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Cloudflare Docs

Docs Directory APIs SDKs

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.

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