Get up and running in minutes

Get more users by offering one-click sign in for 500 million Office 365 and enterprise accounts

ww w . c o n t o s o . c o m Sign in T r y y o u r w o r k o r s c h o o l a c c o u n t
Hi, {0}! Sign out

We support iOS, Android, web, and more.  You bring your users and your stack, we'll make it work.

Build amazing apps with Microsoft APIs

Access user data inside the enterprise — get an Office 365 user's calendar, mail, and contacts. Perfect for driving fast growth.

Used by 85% of the Fortune 500

The Microsoft identity stack has been battle tested by some of the biggest companies in the world.

Hundreds of apps are using Microsoft to sign in users, including

Get started with just a few lines of code

Sign In
Register app
Get code
Get users

Select a platform for step-by-step instructions

Powerful identity features

Hybrid Identity
Our login works across cloud and on-premises Active Directory, allowing users to sign in with their existing credentials.
Multi-Factor Authentication
Ensuring customer security is critical, which is why we make it easy to configure multi-factor authentication. If used by your customers, our SDKs automatically make your application compliant.
Enterprise Grade
Powerful, reliable, and secure. We run a geo-replicated service with automatic failover so users can authenticate 24/7, with guaranteed 99.9% availability.
Single Sign On
We support seamless single sign on, so if you have multiple applications on the same device a user logging into one is automatically logged into the rest of your applications as well.
Cross Platform
We provide a consistent experience across multiple form factors and multiple operating systems including iOS and Android, so your customers can continue using the devices they love.
Multiple SDKs
We provide SDKs for many popular technology stacks, including JavaScript, iOS, and Android. Our SDKs give you the fastest, easiest, and most secure way to integrate with our platform.
Industry Standard Protocols
We support OAuth 2.0, OpenID Connect, SAML 2.0, and WS-Federation 1.2. In addition, since we’re standards compliant you can choose to code against the protocol directly.
Microsoft APIs
Using our identity platform allows you to access a wealth of powerful data and functionality through the various Microsoft APIs, including Microsoft Graph, Azure AD Graph, and the Skype API.

More resources

iOS is a registered trademark of Apple Inc, registered in the U.S. and other countries. The Android robot is reproduced or modified from work created and shared by Google and used according to terms described in the Creative Commons 3.0 Attribution License.