What is Azure Web PubSub?
Azure Web PubSub is a fully managed real-time messaging service that provides WebSocket connections for web, mobile, and server applications. The service handles all connection management and scales elastically across multiple units, with each unit supporting a fixed number of concurrent connections. Web PubSub supports native WebSocket connections as well as its own subprotocol (json.webpubsub.azure.v1) for structured publish/subscribe communication.
Unlike Azure SignalR Service, which provides an abstraction for .NET developers, Web PubSub is a low-level service for any language and any client that supports WebSockets.
Key Features
- Native WebSockets: Standard WebSocket protocol without proprietary client libraries
- Publish-Subscribe: Group-based messaging for efficient broadcasts to many clients at once
- Event Handlers: Serverless integration with Azure Functions or via webhook for incoming client events
- Client Permissions: Granular access control via JWT-based authentication and role-based group permissions
- Scalability: Free, Standard, and Premium tiers; the Premium tier additionally offers a Premium_P2 SKU for especially high scaling requirements
Typical Use Cases
Live Dashboards: Real-time updates for monitoring dashboards, stock prices, or gaming leaderboards.
Collaborative Apps: Multi-user editors, whiteboards, or project management tools with live synchronization.
Live Notifications: Push notifications for social media feeds, chat applications, or alert systems.
Benefits
- No Server Infrastructure: Fully managed with automatic scaling and patches
- Platform Independent: Standard WebSocket for browsers, mobile apps, and IoT devices
- Serverless Integration: Integration with Azure Functions and Event Hubs for event-driven architectures
- Predictable Costs: Billed by units and outbound messages, with a daily free quota per unit
Frequently Asked Questions about Azure Web PubSub
What is the difference from Azure SignalR Service?
SignalR Service is optimized for .NET developers with the SignalR library and offers features like automatic reconnect and fallback protocols. Web PubSub is a low-level WebSocket service for any language without proprietary dependencies.
How many concurrent connections are supported?
One unit supports 1,000 concurrent connections. Standard instances can scale to 1, 2, 5, 10, 20, 50, or 100 units. The Premium tier additionally offers a Premium_P2 SKU that allows scaling up to 1,000 units for especially demanding scenarios.
How do I authenticate clients?
Web PubSub uses JWT tokens for authentication. Your own server generates tokens with claims for user ID, group membership, and permissions (for example, send, receive, join group).
Which protocols are supported?
Native WebSocket (ws/wss) is the standard. Additionally, there is the json.webpubsub.azure.v1 subprotocol for structured messages with system events and direct publish/subscribe between clients, without every message having to pass through your own server.
What does Azure Web PubSub cost?
Billing is based on the number of provisioned units and the volume of outbound messages. There is a free tier for testing as well as Standard and Premium tiers for production scenarios, each with a daily free quota of outbound traffic per unit. Current prices are available on the official pricing page.
Integration with innFactory
As a Microsoft Solutions Partner, innFactory supports you with Azure Web PubSub: from real-time application architecture to integration with existing backends to implementing scalable messaging solutions.
Note: All product information on this page has been compiled with care, but is provided without guarantee and may be outdated or incomplete. Cloud services evolve rapidly — features, pricing, SLAs, and availability change frequently. Authoritative and up-to-date information can only be found on the official product page of Azure (official documentation). This page does not represent an offer by Azure.
