A Practical Guide to WebSockets and Real-Time Features
A protocol that keeps a two-way connection open between browser and server, used for chat, live dashboards, notifications and collaborative editing.
Marcus Adeyemi
The key figures
- WebSocket protocol
- RFC 6455
- Server-sent events
- one-way server-to-browser streaming over HTTP
- Connection handling
- clients must reconnect after network changes
- Scaling
- open connections consume server resources
Why this is worth getting right
Real-time features need a different architecture from ordinary requests, and choosing between WebSockets, server-sent events and polling affects cost and reliability.
Do this, not that
Do
- Use server-sent events when only the server sends updates
- Implement reconnection with backoff
- Authenticate connections and check permissions per message
- Plan for scaling open connections
- Fall back gracefully when connections drop
Don’t
- WebSockets for data that rarely changes
- No reconnection logic
- Broadcasting sensitive data to all clients
- Assuming connections stay open on mobile
When to bring in help
Our advice Bring in help when adding chat, live updates or collaboration features, or when real-time features become unreliable at scale.
Where this comes from
- MDN Web Docs — The WebSocket API
- RFC Editor — RFC 6455 The WebSocket Protocol
- MDN Web Docs — Using server-sent events
The figures and practices above come from the sources listed.
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Where to go next
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