Understanding the AADSTS50011 Redirect URI Mismatch Error

If you’ve ever tried setting up Microsoft authentication and hit a roadblock, chances are the AADSTS50011 redirect URI mismatch error popped up like an uninvited guest. This error is infamous among developers and admins working with Microsoft Entra ID (formerly Azure Active Directory), Microsoft 365, and integrations in Azure or Power Platform.

Why does it matter? This glitch can bring your login flows to a screeching halt, leaving users unable to sign in and applications stuck outside the gates. Redirect URI mismatches are a common trap that snags both new projects and changes to existing setups. Getting to grips with what triggers AADSTS50011—and knowing how to fix it—not only keeps your apps running smoothly, it’s critical for securing authentication and authorization with Microsoft’s platforms.

In this guide, you’ll see what causes the error, how to spot its symptoms, and get practical tips for finding and fixing those mismatched redirect URIs. Even if you’re brand new to Microsoft authentication, you’ll walk away ready to troubleshoot and lock down your sign-in flows the right way.

What Is Causing the AADSTS50011 Error?

The root cause of the AADSTS50011 error is a mismatch between the redirect URI used by your application and the list of URIs registered within Microsoft Entra ID. When someone tries to sign in, Microsoft’s authentication system checks that the redirect URI sent in the OAuth or OpenID Connect request exactly matches one on file for the app registration.

This strict security check prevents unauthorized endpoints from intercepting user tokens—a cornerstone of modern identity protection. If there’s any difference—even a stray slash, the wrong protocol (like http instead of https), or a typo—Entra ID instantly blocks the sign-in and throws the AADSTS50011 error. Understanding this safeguard helps you not only resolve errors faster, but also avoid risky misconfigurations going forward.

Problem Symptoms and Error Messages to Watch For

• Microsoft Sign-In Screen Errors: Users see a bold “AADSTS50011: The reply URL specified in the request does not match...” message after attempting to log in. This is often displayed on the Microsoft sign-in splash page and stops authentication cold.
• OAuth Error Codes in API Calls: Apps integrating with Microsoft APIs receive error objects containing “error=invalid_request” or “error=AADSTS50011” in their API or redirect responses, signaling a mismatch behind the scenes.
• Authentication Failure Logs: In Azure or Entra ID logs, admins notice failed login attempts with explicit mentions of redirect URI mismatches, often with details about the expected versus actual URIs.
• Web App Login Failures: End users may report looping logins, blank screens, or being kicked back to the home page unexpectedly—especially right after redirecting to or from a Microsoft login.
• Backend System Errors: Automated platforms (like email processors or scheduled jobs) might log or display the AADSTS50011 code, especially when attempting OAuth flows from different environments (dev, staging, production).

Fixing the Redirect URI for Resolution of AADSTS50011

The good news is, resolving AADSTS50011 is usually a matter of detective work and careful double-checking—no magic required. At a high level, you’ll need to bring the redirect URI used by your application into exact alignment with those registered in the Azure portal under your app registration. Even tiny differences in protocol, spelling, or slashes can cause the mismatch, so attention to detail is the name of the game.

Fixing this isn’t only about stopping errors. Keeping your redirect URIs straight is essential for Microsoft authentication security. Entra ID expects precision to prevent attackers from intercepting tokens or exploiting weak points in your login flow. That’s why you want to be extra careful when adding or editing URIs, and why it pays to review them any time you change environments or hostnames.

Behind the scenes, Microsoft insists that the redirect URI sent on a login attempt matches exactly what’s listed for your application. This matching goes all the way down to casing, trailing slashes, and the use of HTTPS—which keeps you, your users, and your organization safe from redirect attacks. With multiple devices, code changes, and environments in play, it’s easy for mismatches to sneak in, but a solid process for registering and reviewing URIs means you’ll rarely see this error again.

If you're interested in tightening your security measures even further—especially against OAuth consent attacks—explore resources like this detailed guide on OAuth consent abuse and Entra ID controls. Staying ahead of both configuration snafus and evolving threats makes for a more resilient authentication setup.

Common Causes Behind Redirect URI AADSTS50011 Errors

• Typographical Errors: Even a single letter out of place will prevent the redirect URI from matching those registered, triggering the AADSTS50011 error.
• Protocol Mismatches (HTTP vs HTTPS): Using http when Azure expects https—or vice versa—results in a mismatch, since Microsoft is strict about security.
• Missing or Extra Slashes: A trailing slash at the end of the URI (or the lack of one) can make or break an exact match.
• Case Sensitivity Issues: URIs in Azure are case-sensitive. If your request is for /Callback but registration lists /callback, the error will appear.
• Wrong Environment URL: Mixing up development, staging, or production URLs—like using localhost in production—can create mismatches fast.

How to Register and Verify Redirect URIs in the Azure Portal

• Locate Your App Registration: In the Azure portal, navigate to “App registrations” and select the application in question.
• Edit Redirect URIs: Under “Authentication,” find the Redirect URIs section and add, delete, or update the necessary URIs.
• Match Exact Details: Ensure every detail matches your code or deployment—protocol, domain, path, trailing slash, and case.
• Save and Confirm: After editing, hit save. Double-check that all redirect URIs now align with those used in your application config or codebase.
• Test Authentication Flow: Try signing in again to confirm that the error is resolved and the redirect behaves as expected.

More Information, Resources, and Community Feedback

Wrapping up the redirect URI mismatch struggle? Good news—you don’t have to wing it alone. Microsoft delivers a mountain of documentation and useful references to keep you out of trouble next time. If you’re looking for the nitty-gritty details, start with their official error code docs for authentication and authorization issues in Entra ID (formerly Azure AD). These guides walk you through common missteps and how to undo them, plus they offer code samples for all you tinkerers.

Of course, sometimes docs don’t hit the weird edge cases. That’s where community forums become your lifeline. Microsoft Q&A, Stack Overflow, and feedback threads are packed with real war stories from folks who have wrestled—and pinned—the dreaded AADSTS50011. Jump in with your symptoms, or scroll through solved threads and see if your fix is hiding in plain sight. It’s like having a whole support group dedicated to your headaches.

For more on keeping your apps—and your organization—safe and sane, check out the bigger picture around cloud governance and identity security. Want to keep policy drift and configuration chaos at bay? Dip into this primer on Azure enterprise governance strategy. Want the lowdown on airtight identity practices? This discussion about reducing identity risk with Entra ID conditional access is for you.

If you found this helpful, or ran into something unusual, share your feedback or drop your workaround in the comments. The more you contribute, the easier it is for the next engineer to escape the redirect URI quicksand. Who knows—your insight might be the missing puzzle piece for someone else tomorrow.