How does the internet actually work?

Watch your message leave your laptop, cross the world, and come back.

Start here

6 short steps · about 30 minutes

  1. You

    Your laptop sends a message.

  2. Wi-Fi

    Radio waves carry it across the room.

  3. Home router

    It leaves your house here.

  4. Internet provider

    Your provider points it the right way.

  5. Ocean cable

    Light in glass crosses the sea.

  6. The website's data centre

    A computer reads it and replies.

Your message leaves your laptop, crosses the room over Wi-Fi, goes out through your home router to your internet provider, and travels along a cable under the ocean to the website’s data centre. The reply comes back the same way.

Your path

  1. Step 1: What happens when you open a website?
  2. Step 2: Your devices are on a network
  3. Step 3: Messages travel in small packets
  4. Step 4: Finding a website's address
  5. Step 5: Asking for the page
  6. Step 6: Keeping it private with HTTPS

Explore by question

How does data get from one place to another?

  • Network Map

    What is a network made of?

    Beginner8 minSimulated

  • Packet Journey

    How does a message travel across the internet?

    Beginner10 minSimulated

What happens when I open a website?

  • Internet Simulator

    What happens when you type a web address and press Enter?

    Beginner10 minSimulated

  • DNS Explorer

    How does your computer find a website's address?

    Beginner8 minSimulated

  • HTTP Explorer

    What does your browser actually say to a website?

    Intermediate10 minSimulated

  • HTTPS Explorer

    How does the padlock keep what you send private?

    Intermediate10 minSimulated

How do apps talk to servers?

  • API Visualizer

    How do apps ask servers for data?

    Intermediate10 minSimulated

  • WebSocket Viewer

    How do chat apps get new messages instantly?

    Advanced8 minSimulated

How do people check a network?

  • Network Diagnostics

    How do people check whether a website is reachable?

    Intermediate8 minLive network

Where do I start?

Everything here runs in your browser, except Network Diagnostics’ Live mode, which only runs when you switch it on.