Kinde is a developer platform for authentication (checking who a user is at login), access management (deciding what each user may do) and billing, for SaaS products. It is made by Kinde Australia Pty Ltd.
A developer adds a Kinde SDK to the application, with official SDKs for Next.js, React, Node.js, Python, PHP, Ruby, Java, .NET, iOS, Android, Flutter and other platforms, and sends users to login pages that Kinde hosts and that can be styled and placed on the product's own domain. Kinde supports password and passwordless login, social logins, multi-factor authentication (a second check such as a code sent by SMS), and enterprise single sign-on (SSO) through Microsoft Entra ID or SAML, so that a company's staff log in with their work account. It also manages organizations for B2B products, custom roles and permissions, machine-to-machine (M2M) access for back-end services, feature flags (switches that turn a feature on for some users only) and separate environments. Its billing feature charges the product's customers for subscriptions.
It is a hosted service with a free plan and monthly subscriptions, plus a percentage of each customer transaction when Kinde billing is used.