Skip to content

Build a WebSocket Server

Build a WebSocket server from scratch: HTTP upgrade handshake, frame format with masking, fragmented messages, ping/pong keep-alive, close handshake, and scaling considerations. The protocol behind Slack, Discord, Figma, and every real-time web app.

intermediate13 lessons4 chapters13 graded exercisesPython
Start course — it’s freeWork in your own editor

No sign-up needed for lesson 1 · certificate on completion · sign up to save progress

What you’ll have built

Chapter by chapter. Every step is a graded exercise.

  • Handshake & Upgrade
  • Frame Format
  • Operations
  • Production
Starts in Python — solve in the language you choose in the editor, same tests either way.

Curriculum

4 chapters, 13 lessons. Each lesson is a short read, one graded exercise, and a quiz.

  1. 1Why WebSocketsRead · exercise · quiz
  2. 2The Upgrade HandshakeRead · exercise · quiz
Loading reference solution…