Ably is a realtime infrastructure platform for chat, pub/sub messaging, and live data at scale. See pricing, features, pros and cons, and FAQs.
Ably is a managed realtime infrastructure platform that lets developers add pub/sub messaging, chat, presence, and live data streaming to applications without building and scaling their own WebSocket or long-polling servers. Founded in London in 2013 by Matthew O'Riordan and Dr. Paddy Byers, the company spent several years engineering a globally distributed edge network before launching its core platform in 2016.
Rather than a single product, Ably operates as a platform of realtime primitives: channel-based publish and subscribe, presence tracking, message history, and connection recovery, all exposed through REST, WebSocket, MQTT, and SSE interfaces. On top of this core, Ably has built specific products such as Ably Chat and Ably Spaces to shortcut common realtime UX patterns like typing indicators and multiplayer cursors.
The platform is aimed at engineering teams, from early-stage startups to large fintech, media, and gaming companies, that need dependable message delivery and ordering guarantees at scale, without operating the underlying infrastructure themselves.
Ably's pub/sub core guarantees message ordering and delivery across a globally redundant edge network, with message history and stream resume so clients can recover missed data after a disconnect. Presence tracking lets applications show who is online in a channel or collaborative space in real time.
Purpose-built products reduce the engineering lift for common patterns: Ably Chat provides a ready-made chat API with reactions and moderation hooks, and Ably Spaces handles multiplayer presence and cursor sharing for collaborative tools.
Ably also supports push notifications, multiple protocols (REST, WebSocket, MQTT, SSE), and integrations that stream events into systems like Kafka, AWS Lambda, and Kinesis, making it usable as both a frontend realtime layer and a backend event distribution system.
Ably offers a free tier covering roughly 200 concurrent connections, 500 messages per second, and 6 million messages per month, suitable for prototypes and small production apps. Paid plans start with Standard at $29 per month plus usage, and Pro at $399 per month plus usage, each raising channel, connection, and throughput limits and adding faster support SLAs.
Usage-based charges apply on top of the monthly platform fee for messages, connection minutes, channel minutes, and data transfer, with per-unit rates dropping at higher volumes. Billing can alternatively be based on monthly active users for consumer apps with unpredictable traffic patterns.
Enterprise plans are custom-priced and add unlimited capacity, 24/7 mission-critical support, uptime SLAs up to 99.999 percent, and committed-use discounts, typically negotiated directly with Ably's sales team.
Ably is used to add realtime features such as chat, live notifications, collaborative cursors, live data dashboards, multiplayer state sync, and IoT telemetry streaming to applications without running custom WebSocket infrastructure.
Yes. Ably's free plan supports up to 200 concurrent connections, 500 messages per second, and 6 million messages per month, enough for prototypes and many small production apps.
Ably charges a monthly platform fee on paid plans plus usage-based charges for messages, connection minutes, channel minutes, and data transfer, or alternatively bills by monthly active users. Enterprise plans use custom contracts.
Ably supports REST, WebSocket, MQTT, and Server-Sent Events, and provides client SDKs for languages including JavaScript, Python, Java, Swift, and Kotlin.
Ably can replace self-managed WebSocket layers and offers similar realtime capability to Firebase's realtime features, but with stronger delivery guarantees, multi-protocol support, and enterprise SLAs.
Ably was founded by Matthew O'Riordan and Dr. Paddy Byers, with the company established in 2013 and its core platform launching in 2016.
Ably is headquartered in London, United Kingdom.
Yes, Enterprise plans include uptime SLAs of up to 99.999 percent, along with 24/7 mission-critical support.