CORS errors are one of the most common “why won’t this just work” moments in web development, and the fix is almost always a handful of headers configured slightly differently per framework. This tool generates a starting snippet for the framework you’re actually using.
What Is the CORS Config Generator?
CORS Config Generator is one of the tools in WebdevToolbox’s Networking category. Enter your allowed origins, methods, and headers, toggle credentials support, and get a ready-to-adapt snippet for Express, Next.js, Vite, or Nginx.
How to Use It
- Open the tool at /tools/cors-generator.
- Enter allowed origins, methods, and headers.
- Toggle “Allow credentials” if your app needs cookies or Authorization headers sent cross-origin.
- Pick your framework and copy the generated snippet into your server config.
Key Features
- Four framework targets — Express (Node.js), Next.js API routes, Vite dev server, and Nginx.
- Credentials-aware output — reflects your chosen origin appropriately when credentials are enabled.
- Live regeneration — change any field and the snippet updates immediately.
- Copy-ready snippets — paste directly into your project as a starting point.
When to Use the CORS Config Generator
- Setting up a new API — get a correct starting CORS config instead of guessing at header names.
- Debugging a CORS error — compare what you have against a known-good baseline for your framework.
- Switching frameworks — quickly translate a CORS policy you already understand into a new framework’s syntax.
Try It Now
Open CORS Config Generator directly from anywhere on the site using ⌘K and typing the tool name. No login required — everything runs offline-capable in your browser.
Part of the Networking collection on WebdevToolbox — free, browser-based developer tools with no login required.