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🔒 API Security & Auth Header Decoder

Basic Auth Decoder & Header Generator

Decode Authorization: Basic ... headers to extract credentials, or generate formatted Basic Auth headers for cURL, Postman, and REST APIs.

Mode:
100% Offline • Credentials Kept in Browser Memory
Authorization Header or Base64 String
Decoded Credentials

Understanding HTTP Basic Authentication

Basic Auth is a simple challenge-response authentication scheme defined in RFC 7617. Client requests transmit credentials in the Authorization request header.

Frequently Asked Questions

How does HTTP Basic Authentication encode credentials?

HTTP Basic Authentication combines the username and password with a colon ('username:password') and encodes the resulting string in Base64: 'Authorization: Basic base64(username:password)'.

Is it safe to decode Basic Auth headers in this tool?

Yes, 100% safe. Decoding runs locally in your browser memory. No usernames or passwords are ever logged or sent to an external server.

How do I generate a Basic Auth header for cURL or Postman?

Switch to 'Generate Basic Auth Header' mode, enter your username and password, and copy the generated 'Authorization: Basic ...' header or complete cURL command snippet.

Is Basic Authentication encrypted by default?

No! Base64 is merely an encoding format that can be trivially reversed. Basic Auth must always be transmitted over HTTPS (TLS encryption) to prevent credential sniffing on the network.

Can I decode Basic Auth headers containing emails or special characters in the password?

Yes! Special characters (like @, #, $, %, ^, &) are fully decoded.

How do I pass Basic Auth in JavaScript Fetch?

Pass the header: 'fetch(url, { headers: { "Authorization": "Basic " + btoa(username + ":" + password) } })'.