HTTP vs HTTPS — What's the Difference?

HTTP transmits data in plain text between client and server; HTTPS adds a layer of TLS encryption on top of HTTP, protecting data in transit from being read or tampered with.

Why they differ

• Without encryption, HTTP traffic can be intercepted and read by anyone with access to the network path, such as on public WiFi
• HTTPS also verifies the server's identity via a certificate, protecting against impersonation, in addition to encrypting the data

How to choose

• Modern browsers mark plain HTTP sites as "Not Secure" and increasingly restrict features (like geolocation) to HTTPS-only
• Free, automated certificates (e.g. via Let's Encrypt) have made HTTPS the practical default for virtually every public website today

FAQ

Does HTTPS slow down a website?

Modern TLS adds only a small, largely negligible overhead — the security benefit far outweighs the minor performance cost on virtually all real-world sites.