Extend Kafka to end-users at the edge

Enhance and reliably expand Kafka's event streaming capabilities beyond your private network. Ably offers a simple, dependable, scalable, and secure way to distribute messages from Kafka to web, mobile, and IoT clients anywhere in the world.

Companies building on Ably

Provides realtime sports data and odds for sports, betting, and media companies around the world.

Realtime patient engagement and care scheduling for 60k+ patients/day.

Powers live chat, updates, analytics, and composition for millions of users.

Maximize the value of your Kafka pipeline

Augment your Kafka pipeline seamlessly with dependable last-mile messaging:

  • Fast and scalable event streaming to client devices the edge with no additional infrastructure to provision or manage.

  • Create dependable digital experiences for your end-users with guaranteed message ordering, delivery, and exactly-once semantics.

  • Robust security and privacy guarantees when you expose Kafka data to clients over the public internet.

Ably is an enterprise-grade serverless WebSockets platform designed for pub/sub messaging at the edge. We deliver 550+ billion messages to more than 250+ million end-users each month.

Build collaborative user experiences. Not the infrastructure to power it

Ably and Kafka are complementary solutions

Both Ably and Kafka are event-driven solutions, sharing similar guarantees, messaging semantics, and characteristics. With Ably as a broker in the middle, you can seamlessly and scalably distribute Kafka data to web, mobile, and IoT clients at the edge.



Distributed pub/sub solution built for streaming messages within a private network (intranet). Enables event-driven communication between various backend components.


Distributed pub/sub platform built for streaming messages to the edge, across network boundaries. Powers synchronized digital experiences in realtime for web and mobile app users.



Custom binary protocol over TCP.


Supports multiple open protocols suitable for last-mile delivery, such as WebSockets, SSE, and MQTT.



Supports various security mechanisms designed for internal event streaming, including cluster encryption and authentication.


Robust and diverse security mechanisms for data delivery over the public internet, including flexible authentication with fine-grained access control and 256-bit AES encryption.



Achieves sub-second latencies.


<65 ms median round-trip latency from publishing into Ably to end-users at the edge.



Can be configured to ensure ordering at partition level, and to guarantee exactly-once semantics.


Guaranteed message ordering, delivery, and exactly-once semantics, even in unreliable network conditions.



Works best with a low number of topics, and a defined, predictable number of producers and consumers. Scalable, but capacity needs to be provisioned in advance.


Designed to work with an unknown and rapidly changing number of channels (Ably's equivalent of topics) and subscribers. Ably can quickly scale horizontally to handle millions of consumers.



Fault-tolerant by design, with each partition being replicated over a configurable number of servers. This allows automatic failover to replicas whenever a server in the cluster fails.


Designed to be fault-tolerant at regional and global levels, with no single point of failure.


Ably is awesome. It was a life-saver for me. Not only was it the only HIPAA-compliant realtime solution capable of integrating with Kafka streams and giving us the performance guarantees we need, but the set-up was just incredibly straightforward. It instantly transformed the value of the dashboard for our customers.

Andrew HanischSystem Architect, Experity

Ably's features


Presence allows you to automatically track and communicate the online status of your users. Use it to build an avatar stacks, typing indicators, cursor tracking and more.

STATE Synchronization

All user actions and changes are synced correctly and at low latency.


Distribute events to millions of subscribers over channels that support multiplexing with Ably’s feature-rich pub/sub APIs. We ensure delivery of the right message to the right client in realtime.


On disconnect we keep state and retry connection every 15 seconds for two minutes, meaning users receive a seamless collaborative experience with messages arriving in the correct order.


Reduces the bandwidth needed to distribute messages (events) to consumers by sending only the changes from the previous message instead of the entire payload.


We guarantee ordering, delivery, and exactly-once semantics from the moment an event is published to Ably, all the way to its delivery to consumers.

Easy integration with the Ably Kafka Connector

The Ably Kafka Connector is a sink connector built on top of Kafka Connect. It provides a ready-made integration enabling data from Kafka topics to be published into Ably with ease and speed. Events are then distributed in realtime to web, mobile, and IoT clients over feature-rich, multi-protocol pub/sub Ably channels optimized for last-mile delivery.

The connector can be self-hosted, or hosted with a third-party provider such as the Confluent Platform. The Ably Kafka Connector is a Verified Gold Connector on Confluent.

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Works with any type of Kafka deployment that includes Kafka Connect

Kafka topics & Ably channels

Scalable data streaming to the edge with no infrastructure overhead

While Kafka works best with a defined and predictable number of topics and consumers, Ably is optimized to distribute data to an unknown and rapidly changing number of end-user devices. Our platform is powered by a dynamically elastic and highly available global edge network that can quickly scale horizontally to an unlimited number of channels and millions of concurrent subscribers.

You don't have to manually provision capacity or manage infrastructure, and with our flexible pricing model, you will only pay for what you use.

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Create dependable realtime experiences at scale

Ably was built from the ground-up to be the trusted infrastructure that supports complex, business-critical, realtime experiences in fast-growing scenarios. Our mathematically modelled approach to system design ensures critical functionality at scale and provides unmatched quality of service guarantees, enabling you to create dependable digital experiences that will delight your end-users.

Ably’s Four Pillars of Dependability


We focus on predictability of latencies, and we guarantee <65 ms round trip latency for 99th percentile. We also provide unlimited channel throughput.


Message ordering, guaranteed delivery, and exactly-once semantics are built-in, from the moment a message is published to Ably, all the way to its delivery to consumers.


Fault tolerance at regional and global levels to guarantee continuity of service even in the case of multiple infrastructure failures. 99.999999% message survivability.


Ably is meticulously designed for high availability and extreme scale. We ensure 50% capacity margin for instant surges, and provide a 99.999% uptime SLA.

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Ably is one of the key technologies that underpins our business. Its realtime experience infrastructure seamlessly supports HubSpot's entire realtime needs, helping us to meet our technical, business, and product development requirements. With Ably, we have innovated and taken new products to market much faster while significantly reducing our operational engineering overhead.

Max FreiertProduct Group Lead, HubSpot
SOC 2 Type 2
256-bit AES
EU & US-only
Data storage
Keep your Kafka data secure

By using Ably as an edge messaging layer, you decouple your backend Kafka deployment from end-users connecting over the public internet, and protect the integrity of your event-driven pipeline at all times.

Clients never connect directly to Kafka. Instead, they are only allowed to subscribe to the Ably channels for which they have permission from you.

In addition, our platform provides robust security mechanisms suitable for event streaming across network boundaries:

  • Message-level encryption.

  • DoS protection and rate limiting.

  • Flexible authentication (API keys and tokens), with fine-grained access control.

Furthermore, Ably is SOC 2 Type 2 certified and is compliant with standards such as HIPAA.

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