Simple JavaScript requests

GET request with response exposing a header

Summary

When JavaScript code makes a cross-origin GET request, the response can optionally expose headers to it. The Access-Control-Expose-Headers response header must be set, with a comma-separated list of header names to be exposed.

Instructions

1. Hit green button below and see best-header-ever header value
2. Observe difference between source and request origins, confirming cross-origin request