Real-Time Without The Complexity: Fanout for Edge WebSockets & Pub/Sub

Deliver sub-second real-time experiences for chat, live auctions, IoT, and more. Fastly Fanout manages WebSockets, HTTP, and TLS connections, bringing real-time communications and pub/sub patterns to the edge. Connect to any client from one backend, build MQTT applications, offload WebSockets, or even orchestrate events across the web - all at Fastly scale. 

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The Event-Driven Foundation for Modern Real-Time Apps

Leverage Fanout to manage the complexity of bi-directional communication, for everything from WebSockets to IoT sensor data. By handling connection state and protocol translation at the edge, you minimize origin load, ensure low-latency delivery, and increase your team's development speed.

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  • Dramatically Reduce Origin Load and Infrastructure Costs

    Fanout can manage millions of concurrent, stateful WebSocket or HTTP streaming connections at the edge, letting you relay simple HTTP requests to your origin. This can significantly offload server demand, drive system resilience, and deliver strong ROI.

  • Accelerate Developer Velocity and Time-to-Market

    Build on a flexible platform that speaks WebSockets, HTTP, and TLS. Focus on business logic - not connection management - and build pub/sub, IoT, MQTT, and other real-time solutions.

  • Unify Real-Time Communication Across Protocols

    With its strong HTTP/WebSockets foundation, Fanout lets services respond to requests from web traffic, WebSockets, or even inbound IoT data — and even translate between them. Fanout can manage connection state, coordinating with your origin via simple HTTP to offload resources and complexity.

WebSockets Pass-Through vs. Fanout: Choosing the Right Real-Time Strategy

Fastly's platform supports all real-time needs. Our pass-though WebSockets product provides a direct, bi-directional path through the CDN for self-managed infrastructures. Fanout is our event-driven solution for building more robust real-time applications, managing connection state, translating protocols, and dramatically offloading your origin. Use the information below to determine which solution best fits your use case.

  • WebSockets Pass-Through

    Best for: Securing existing real-time data Infrastructure.

    • Primary connection model is 1:1, Bi-directional (Client to Origin)
    • Origin server manages all connection state.
    • No protocol translation. Requires origin to speak WebSockets.
    • Minimal origin offload & ROI. Origin must maintain concurrent connections.
    • Billing model = connection time.
    • Supports any use case that requires running your real-time data infrastructure at the origin.

  • Fanout (Push data at the edge)

    Best for: Offloading the burden of operating real-time data infrastructure at the origin.

    • Primary connection model is 1:Many, Push/Pub-Sub (Event driven)
    • Fastly Fanout manages all connection state at the edge.
    • Fastly Fanout handles protocol translation. (e.g., WebSockets to Origin-friendly HTTP)
    • Maximum origin offload & ROI. Origin handles simple HTTP events and business logic.
    • Billing model = connection time and messages.
    • Provides real-time data at the edge for Live Auctions, Sports Scores, Stock Tickers, Real-Time Push Notifications, IoT Coordination (MQTT), Multi-User Chat.

Push Architecture Done Right

No need to build your own "stream server thing". We've done the hard work for you.

  • Hybrid reverse proxy and message broker.

    Augment your existing API with push capability.

  • Designed for interoperability.

    Any HTTP-based backend, including serverless/FaaS, can manage long-lived streams.

  • Self-hosted or cloud. It’s up to you.

    Use our massive network with a custom domain name or run the software on your own servers.

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IoT

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"It would be challenging to accomplish what we're doing without Fastly. Edge computing is key to our technology."

Ryan Minor

Mobile and IoT Development Manager

WebSockets & Fanout

Push real-time data to any devices, anywhere
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