PureDevTools

CORS Header Builder

Generate correct CORS headers for your API in seconds

All processing happens in your browser. No data is sent to any server.

Use * for all origins, or comma-separated specific origins.

Allowed Methods

Output Format

HTTP Response Headers
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST, OPTIONS
Access-Control-Allow-Headers: Content-Type, Authorization
Access-Control-Max-Age: 86400

Why This Tool

CORS errors are one of the most common frustrations in web development. Getting the right combination of Access-Control-Allow-Origin, Allow-Methods, Allow-Headers, and preflight settings is tedious and error-prone. This tool builds the correct headers for your use case and generates copy-paste ready configuration snippets.

How It Works

Select your allowed origins, methods, and headers using the visual interface. The tool generates the complete set of CORS headers along with implementation snippets for popular frameworks like Express, Nginx, Apache, and Cloudflare Workers. Copy the config directly into your project.

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