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Polling vs. WebSockets vs. Server Actions

January 8, 2025 • 16 min read

Polling

  • •Easy to debug – it's just a request on a timer
  • •HTTP-based – works with the REST APIs you already have
  • •Wasteful – most requests come back saying nothing changed

WebSockets

  • •Instant, both directions – the server can push
  • •Cheap once open – no per-message handshake
  • •You now own a connection – reconnects, dropped sockets, scaling

Server Actions

  • •Next.js native – no API route to wire up
  • •Typed end to end – the call and the handler share types
  • •Not for live data – it's request/response, you call it

Three ways to keep a React UI in sync with the server. I've shipped all three, and the thing I keep running into is teams reaching for WebSockets because real-time sounds better, then spending a sprint on reconnect logic for a dashboard that updates every ten seconds. Polling would have been a fetch in a setInterval. Here's how I pick.

When to Use Each Approach

Use Polling For:

  • • Dashboard metrics (5-30 second updates)
  • • Background job status checking
  • • Simple notifications
  • • When WebSocket infrastructure isn't available

Use WebSockets For:

  • • Live chat applications
  • • Real-time collaboration (like Figma)
  • • Live sports scores/trading data
  • • Multiplayer games

Use Server Actions For:

  • • Form submissions with validation
  • • CRUD operations in Next.js
  • • User interactions (likes, follows)
  • • Progressive enhancement scenarios

Performance Comparison

Polling
Latency: 2.5-15s avg
Bandwidth: High (repeated requests)
Battery: Moderate impact
Complexity: Low
WebSockets
Latency: under 50ms real-time
Bandwidth: Low (after setup)
Battery: Higher impact
Complexity: High
Server Actions
Latency: Request-based
Bandwidth: Optimized
Battery: Low impact
Complexity: Low-Medium

My rule of thumb: start with polling. If the lag genuinely hurts the feature and you've measured it, move that one feature to a socket. Forms stay on Server Actions. I've never regretted starting with the boring option, and I have regretted the other way round, when the socket layer became the thing that paged me at the weekend.

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