9-part series
A failed login rarely reports itself honestly. WebAuthn collapses most problems into a single NotAllowedError. Native platforms return their own opaque codes. An OS update can break a flow that worked yesterday. This series works from symptom to cause. How to read WebAuthn and platform error codes. How to spot an OS-update regression. How to isolate a broken device cohort. How to turn one support ticket into a fix you can reproduce.
Each article stands on its own - start wherever your problem is.
Complete reference of Google Play Services passkey error codes (50100-50196) as of GPS v26.06.32. Maps every code to WebAuthn errors.
Complete reference of Apple's passkey error codes across macOS 26.2 and iOS 26.2. Maps ASCAuthorizationError to ASAuthorizationError to DOMException.
Learn how to run root cause analysis for login and authentication failures across passkeys, social login, OTP, browsers and devices.
Native app passkey errors differ drastically between iOS and Android. Learn what breaks, why Android is 3-5x worse and how to measure it.
This blog posts helps to understand common passkey error (messages), what their causes are and how theses passkey problems can be solved.
Passkeys often break inside social-app in-app browsers (Instagram, TikTok, Facebook). Learn why it happens, how to detect WebView traffic and how to route users to a method that works.
QR code login can fail at scan, proximity, device handoff or confirmation. Learn how to debug QR login failures with authentication observability.
Learn what common WebAuthn errors like NotAllowedError mean in production and how to classify them by operation type, timing and platform context.
Why passkeys fail on managed Windows devices, how policy changes create mixed fleets and how to test corporate device readiness.
See every login journey clearly, diagnose failures faster and keep your existing IDP in place.