Security • Published August 20, 2026

Base64 in HTTP Basic Authentication: Header Format, Security & Best Practices

Learn how HTTP Basic Auth uses Base64 encoding in Authorization headers (RFC 7617), why Base64 is not encryption, and how to secure API credentials with HTTPS.

Deep dive into HTTP Basic Authentication (RFC 7617): how Authorization headers use Base64 encoding, credential exposure risks, and mandatory TLS/HTTPS configurations.

Frequently Asked Questions

Q1. How do I construct a Basic Auth header in curl?

Run curl -u "username:password" https://api.example.com or pass the header manually: curl -H "Authorization: Basic dXNlcm5hbWU6cGFzc3dvcmQ=" https://api.example.com.