HTTP vs HTTPS — What Actually Happens When You Visit a Website

By Sailee Shingare | M.S in Computer Science, Northern Illinois University Every time you visit a website, your browser and the server have a conversation. That conversation happens over a protocol — either HTTP or HTTPS. You’ve seen both in your browser’s address bar. But what’s actually different between them, and why does it matter? Let’s break it down. What is HTTP? HTTP stands for HyperText Transfer Protocol . It’s the foundation of data communication on the web — the set of rules that defines how your browser requests information and how servers respond. When you visit a website over HTTP, here’s what happens: You type a URL in your browser Your browser sends a request to the server The server sends back the webpage Your browser displays it Simple. But there’s a problem — everything is sent in plain text . Anyone sitting between you and the server can read it. Your passwords, your credit card numbers, your messages — all visible. This is where HTTPS comes in. What is HTTPS? HTTPS stands for HyperText Transfer Protocol Secure . It’s HTTP with an extra layer of security called TLS (Transport Layer Security) — previously known as SSL. The S in HTTPS means everything between your browser and the server is encrypted . Even if someone intercepts the data, they see nothing but scrambled gibberish. What Actually Happens When You Visit an HTTPS Website When you visit an HTTPS site, your browser and the server perform a TLS Handshake before any data is exchanged. Here’s what happens step by step: Step 1 — Client Hello Your browser says hello to the server and shares which encryption methods it supports. Step 2 — Server Hello The server picks an encryption method and sends back its SSL certificate — a digital document that proves the server is who it claims to be. Step 3 — Certificate Verification Your browser checks the certificate against a list of trusted authorities. If it’s valid, the connection proceeds. If not, you see a warning — “Your connection is not private.”