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CORS Rule Builder

Network & Ops · Free Online Tool

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

By EZ4Code TeamLast updated: 2026-10-29

Allow-Origin

Allow-Methods

Allow-Headers

Expose-Headers

Max-Age (seconds)

Allow-Credentials: true

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

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

Why do geolocation results differ between providers?

Each provider maintains its own IP-to-location database with different update cycles and coverage. Treat any single result as an approximation, not an exact address.