What is WebSocket (WSS)? A Clear Explanation for Beginners (2026)
When I was learning how Polygon data flows to applications, I noticed that some dashboards updated their numbers instantly — new blocks appearing, transactions confirming in real time — without any refresh button. I assumed this was just how the web worked. It isn’t. Standard web requests don’t work this way. What makes real-time blockchain data possible is a technology called WebSocket, accessed through a WSS connection.
WSS vs RPC: The Core Difference
To understand WebSocket, it helps to compare it with RPC — the standard way of communicating with a blockchain node.
You ask a question. The server answers. The connection closes. If you want another update, you ask again. Like sending a text message and waiting for a reply each time.
WebSocket (WSS):
You open a connection. It stays open. The server sends you information whenever something new happens — without you asking. Like a phone call that stays connected while both sides talk whenever they have something to say.
The “WSS” prefix stands for WebSocket Secure — it’s the encrypted version of WebSocket, the same way HTTPS is the secure version of HTTP. When you see a WebSocket URL, it starts with wss:// instead of https://.
How a WebSocket Connection Works
Your application sends a standard HTTP request to the server asking to “upgrade” to a WebSocket connection. If the server supports it, it agrees and the connection switches protocols.
Step 2 — Persistent connection:
Unlike a standard HTTP request that closes immediately after the response, the WebSocket connection stays open. Both sides can send data at any time without re-establishing the connection.
Step 3 — Server push:
When something happens on the Polygon network — a new block, a new transaction, a price update — the server sends that data to your application automatically. You don’t have to keep asking.
Where WSS Is Used on Polygon
Services like Alchemy and Infura provide both HTTP RPC endpoints and WSS endpoints for Polygon. A WSS endpoint looks like this:
Applications that need real-time data — live price feeds, instant transaction confirmations, block explorers that update automatically — use WSS instead of or alongside HTTP RPC. PolygonScan‘s live transaction updates, for example, use WebSocket connections under the hood.
Why Connections Drop — The Silent Failure Problem
Keeping a WebSocket connection alive is harder than it sounds. Internet connections fluctuate. Servers reset. Firewalls close idle connections. When a WebSocket drops, it often fails silently — the application looks fine, the data just stops updating. You might not notice for minutes.
This is why well-built applications implement “reconnection logic” — code that detects when the connection has dropped and automatically re-establishes it. For beginners, this is one of those concepts that sounds simple in tutorials and turns out to be genuinely tricky to implement correctly.
For most beginners using Polygon, you won’t need to manage WebSocket connections directly. DEXs, wallets, and block explorers handle this for you. WSS becomes relevant when you start building applications that need real-time data.
WSS vs HTTP RPC: When to Use Which
• Checking a balance or transaction status
• Submitting a transaction
• Any one-time query where you need one answer
Use WSS when:
• Building a real-time price feed
• Listening for new blocks or specific transaction events
• Any application where you need ongoing updates without constant polling
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