CORS for React Native WebView: A Real-World Fix

Teams hit a weird wall with React Native WebView all the time: the same API call works fine in native code, then suddenly fails when it runs inside a WebView. People call it “a React Native bug” or “an Android thing.” Most of the time, it’s just CORS doing exactly what the browser engine inside the WebView is supposed to do. I’ve seen this happen in hybrid apps that embed a React checkout flow, an admin dashboard, or a support portal. The native shell works. The web app inside the shell blows up with “Network request failed,” “Origin null is not allowed,” or a preflight that never gets approved. ...

July 4, 2026 · 7 min · headertest.com

CORS for Mobile App Backends: What Actually Matters

Mobile developers get told weird things about CORS. I’ve heard all of these: “Mobile apps don’t use CORS.” “Just set Access-Control-Allow-Origin: * and move on.” “CORS is only a frontend problem.” “If the API is private, CORS doesn’t matter.” Some of that is half true, which is usually worse than being completely wrong. If you’re building a backend for iOS or Android, you need to understand when CORS applies, when it doesn’t, and why your support queue suddenly fills up the moment someone adds a webview, an admin dashboard, or a docs playground running in the browser. ...

April 1, 2026 · 7 min · headertest.com