Ably vs Auth0: Which Is Better in 2026?

Ably is a realtime experience and messaging infrastructure platform that provides the building blocks for adding live, scalable features — like chat, presence, live updates, notifications and data broadcasting — to applications. Building reliable realtime functionality is genuinely hard: it requires maintaining persistent connections, handling scale, guaranteeing message delivery and ordering, and managing the complexities of distributed systems. Ably abstracts all of this into dependable infrastructure delivered through simple APIs, so developers can ship realtime features without building and operating the hard underlying systems themselves.

The platform offers pub/sub messaging, presence (knowing who's online), message history, and guaranteed delivery and ordering, all built to scale to millions of connections with high reliability and low latency across a global network. Developers use Ably to power experiences like live chat, collaborative apps, live sports and finance updates, multiplayer features, IoT data streaming, and realtime notifications — anywhere data needs to move instantly and reliably between servers and many clients. With SDKs across platforms and a focus on dependability (including strong delivery guarantees and uptime), it provides the trustworthy realtime backbone that these features require.

Ably is used by companies and developers that need to add realtime functionality to their products and want robust, scalable infrastructure rather than building and maintaining it in-house. By handling the difficult engineering of realtime messaging at scale — connections, delivery, ordering, presence and global distribution — it lets teams focus on their application features and ship realtime experiences confidently. Its emphasis on reliability and scale makes it suitable for serious, production use where realtime data matters. As users increasingly expect live, collaborative and instantly-updating experiences, dependable realtime infrastructure is increasingly important. For developers and companies that want to build live, scalable realtime features without operating the underlying systems, Ably offers a powerful, reliable and well-regarded solution.

Auth0 is an identity platform that lets developers add secure authentication and authorization to their applications quickly, without building and maintaining complex login infrastructure themselves. Authentication is essential to almost every application but notoriously tricky and risky to implement well — handling passwords, social logins, multi-factor authentication, security best practices, and compliance is a lot to get right, and mistakes can be catastrophic. Auth0 provides this as a ready-made, secure service, letting developers add robust login and identity features in a fraction of the time and with far less risk than building from scratch.

The platform supports a wide range of authentication methods — username and password, social logins, enterprise single sign-on, passwordless, and multi-factor authentication — and handles the security details that are easy to get wrong. It offers features for managing users, controlling access and permissions, customising the login experience, and meeting compliance requirements, all through APIs and SDKs that integrate with virtually any application and technology stack. By offloading identity to a specialised, security-focused platform, developers avoid reinventing a complex and high-stakes wheel and benefit from continuously maintained security practices.

Auth0 is used by developers and organisations of all sizes that need reliable, secure authentication without diverting significant engineering effort to building it. The value is security and speed: teams get production-grade, flexible identity management quickly, backed by a platform whose entire focus is doing authentication safely and well. Because getting authentication wrong can lead to serious breaches, relying on a dedicated, expert platform is both a productivity and a security decision. For any application that needs users to log in — which is to say most applications — Auth0 provides a trusted, flexible, and developer-friendly way to handle identity, letting teams focus on their core product while resting assured that a critical and risky piece is handled properly.