This is the simplest and easiest WebSocket library for Unity you can find!

No external DLL's required (uses built-in System.Net.WebSockets)
WebGL/HTML5 support
Supports all major build targets
Very simple API

This WebSocket client is used on colyseus-unity3d.
Consider supporting my work on Patreon.

Installation

Requires Unity 2019.1+ with .NET 4.x+ Runtime

Install via UPM (Unity Package Manager)

Open Unity
Open Package Manager Window
Click Add Package From Git URL
Enter URL: https://github.com/endel/NativeWebSocket.git#upm

Install manually

Download this project
Copy the sources from NativeWebSocket/Assets/WebSocket into your Assets directory.

Usage

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

using NativeWebSocket;

public class Connection : MonoBehaviour
{
  WebSocket websocket;

  // Start is called before the first frame update
  async void Start()
  {
    websocket = new WebSocket("ws://localhost:2567");

    websocket.OnOpen += () =>
    {
      Debug.Log("Connection open!");
    };

    websocket.OnError += (e) =>
    {
      Debug.Log("Error! " + e);
    };

    websocket.OnClose += (e) =>
    {
      Debug.Log("Connection closed!");
    };

    websocket.OnMessage += (bytes) =>
    {
      Debug.Log("OnMessage!");
      Debug.Log(bytes);

      // getting the message as a string
      // var message = System.Text.Encoding.UTF8.GetString(bytes);
      // Debug.Log("OnMessage! " + message);
    };

    // Keep sending messages at every 0.3s
    InvokeRepeating("SendWebSocketMessage", 0.0f, 0.3f);

    // waiting for messages
    await websocket.Connect();
  }

  void Update()
  {
    #if !UNITY_WEBGL || UNITY_EDITOR
      websocket.DispatchMessageQueue();
    #endif
  }

  async void SendWebSocketMessage()
  {
    if (websocket.State == WebSocketState.Open)
    {
      // Sending bytes
      await websocket.Send(new byte[] { 10, 20, 30 });

      // Sending plain text
      await websocket.SendText("plain text message");
    }
  }

  private async void OnApplicationQuit()
  {
    await websocket.Close();
  }

}

Demonstration

1. Start the local WebSocket server:

cd Server
npm install
npm start

2. Open the NativeWebSocket/Assets/WebSocketExample/WebSocketExampleScene.unity on Unity and Run.

Acknowledgements

Big thanks to Jiri Hybek. This implementation is based on his work.

License

Apache 2.0

turol/NativeWebSocket