WebSocket vs HTTP: Understanding the Difference and When to Use Each

Modern applications depend on network communication protocols to exchange data between clients and servers. Two of the most important are HTTP (HyperText Transfer Protocol) and WebSocket. At a high level, both enable communication over the web, but they are designed for different patterns and use cases.

Choosing the right one can boost performance, reduce resource usage, and improve user experience.

For more fundamentals on how applications communicate over networks and how protocols like HTTP enable structured data exchange, check out the MrScraper blog What Is an API Call — A Deep Dive Into How Applications Communicate — it’s a great primer on request–response models and API communication.

What Is HTTP?

HTTP is the foundational protocol of the World Wide Web. It’s designed around a simple request–response model:

1. A client (like a browser or script) sends a request to a server.
2. The server processes that request and returns a response.
3. Once the response is delivered, the connection is typically closed (or reused for another request).

In this pattern, communication always begins with the client asking for something, and the server responding. This works well for traditional tasks like loading web pages, requesting API data, or submitting forms, because each interaction is discrete and independent. A client doesn’t generally stay connected waiting for updates.

Key Characteristics of HTTP

• Stateless: Each request is independent; the server does not retain information about prior requests unless you build that state yourself (for example, using cookies or tokens).
• Unidirectional: The server only responds to client requests.
• High overhead: Every request carries HTTP headers, which can be large compared to the actual payload.

HTTP works on standard ports (80 for HTTP and 443 for HTTPS) and is supported universally across browsers, proxies, and servers. It excels at document delivery, RESTful APIs, and file downloads.

What Is WebSocket?

WebSocket is a protocol designed for bidirectional, real-time communication between a client and a server. It starts with an HTTP handshake but then upgrades to a persistent connection that remains open until explicitly closed by either side.

After the initial handshake (using an Upgrade header), the transport switches from HTTP to WebSocket. Both client and server can send messages at any time, without waiting for a new request.

This enables full-duplex communication, meaning data can flow in both directions simultaneously.

Key Characteristics of WebSocket

• Persistent connection: Reduces the cost of repeatedly establishing connections.
• Bidirectional: Client and server can send messages independently.
• Low latency: Minimal framing overhead after the handshake.
• Real-time support: Ideal for chat, live feeds, games, and collaborative tools.

Because the connection remains open, WebSocket is stateful. The server maintains connection-specific state for as long as the socket is active, unlike HTTP’s stateless model.

How They Work: Side by Side

With HTTP, a client must continually ask the server for new information (polling) if it wants fresh data. WebSocket allows the server to push updates instantly, without new requests.

When to Use HTTP vs WebSocket

Use HTTP When

• You’re building a typical web application where clients request resources as needed.
• Data changes infrequently and doesn’t require instant updates.
• Universal compatibility, caching, and simplicity matter (static content, REST APIs).

HTTP remains the dominant protocol for traditional web traffic because it’s simple, reliable, and supported by virtually every network device, CDN, and proxy.

Use WebSocket When

• You’re building applications that require real-time updates (chat apps, stock tickers, multiplayer games).
• You need server-initiated messages without constant polling.
• Low latency and reduced overhead are critical.

For real-time systems, WebSocket’s persistent connection often delivers significantly better performance than HTTP polling or long-polling techniques.

Practical Considerations

Implementation and Scaling

WebSockets introduce additional complexity. Servers must manage potentially thousands of open, stateful connections and handle reconnections when clients drop. This requires more careful architecture compared to stateless HTTP services.

Firewall and Proxy Support

Although WebSocket starts with an HTTP handshake, some older firewalls or proxies may block or mishandle upgraded connections. Plain HTTP traffic rarely encounters this issue.

Compatibility

HTTP is universally supported and easy to deploy and debug. WebSocket requires modern browsers and WebSocket-aware servers, but support is now widespread across platforms.

Real-World Use Cases

HTTP

• Serving web pages
• REST API responses
• File uploads and downloads

WebSocket

• Live chat systems
• Collaborative editing tools
• Real-time financial data feeds
• Multiplayer games and interactive UIs

Many modern systems combine both approaches: HTTP for general resource delivery and WebSocket for real-time communication channels.

Conclusion

HTTP and WebSocket are both fundamental to web communication, but they solve different problems.

• HTTP excels at delivering discrete resources with stateless, highly compatible interactions.
• WebSocket shines in real-time, bidirectional communication where low latency and persistent connections matter.

Understanding when and how to use each protocol allows you to design systems that deliver better performance, scalability, and user experience.