Skip to content
🔧

CORS Rule Builder

Network & Ops · Free Online Tool

Generate CORS response headers (Access-Control-*).

By CoderNewbie Team
Generated Headers
Access-Control-Allow-Origin: https://example.com
Access-Control-Allow-Methods: GET, POST
Access-Control-Allow-Headers: Content-Type, Authorization
Access-Control-Max-Age: 86400

All CORS Headers

Generates Allow-Origin, Methods, Headers, Expose, Credentials, and Max-Age.

Pre-flight Ready

Output works for both simple requests and OPTIONS pre-flight responses.

Export

Copy or download headers for use in Nginx, Express, or Apache configs.

How to Use CORS Rule Builder

  1. 1Enter the URL, IP address, or network parameter to look up.
  2. 2Click the lookup or test button.
  3. 3Review the detailed results in the output panel.
  4. 4Use the information for your network operations.

Features

  • ✓100% free — no signup, no subscription, no ads
  • ✓Runs entirely in your browser — data never leaves your device
  • ✓Fast and lightweight — instant results
  • ✓Cross-platform — works on desktop, tablet, and mobile

Frequently Asked Questions

Are network lookups real-time?

Yes, IP lookups, DNS queries, and HTTP tests perform live network requests to provide current data.

Is my IP address logged?

The IP Lookup tool queries public geolocation APIs. We do not store your IP address or lookup history.

Related Tools

IP Lookup

Query IP address geolocation and ISP info.

→

Subnet Calculator

Calculate IPv4 subnet details from CIDR.

→

DNS Lookup

Query DNS records via Google DNS over HTTPS.

→

User-Agent Parser

Parse browser, OS, and device from UA string.

→

HTTP Status Codes

Reference for all HTTP status codes.

→

HTTP Request Tester

Send GET/POST/PUT/DELETE requests and inspect responses.

→

Learn the concept

Learn the concept

Understand the programming ideas behind this tool.

View lessons