Pre-flighted JavaScript requests

PUT request with correct CORS setup

Summary

JavaScript code can make a cross-origin PUT request.

The pre-flight response must include the correctly configured Access-Control-Allow-Origin header. The response to the main request must include the same header.

Instructions

1. Press F12 to open browser Developer Tools
2. Open Network tab and filter by path put-success
3. Hit green button below and observe 1 pre-flight and 1 main request