Ready to generate
Enter credentials and click Generate// encode credentials → copy-ready auth header
Generate properly encoded HTTP Basic Auth headers from username and password. Instant Base64 encoding, copy-ready output for curl, Postman, and API testing.
Ready to generate
Enter credentials and click GenerateType your username and password in the input fields.
The tool instantly Base64-encodes your credentials and builds the header.
Copy the Authorization header or grab a ready-made code snippet for curl, fetch, or Python.
HTTP Basic Authentication uses a Base64-encoded string of username:password sent in the Authorization request header. This tool encodes your credentials client-side and outputs the exact header string ready to paste into any HTTP client.
No. All encoding happens entirely in your browser using JavaScript. Your credentials never leave your device and are never transmitted over the network.
The format is Authorization: Basic <base64(username:password)>. The username and password are joined with a colon, then Base64-encoded and prefixed with "Basic ".
Yes. Colons (:) in passwords are technically allowed by RFC 7617 — only the first colon is treated as the separator between username and password.
Basic Auth is only secure over HTTPS. Base64 encoding is not encryption — the credentials can be decoded trivially. Always use TLS/HTTPS when using Basic Auth in production.
Copy the curl snippet from the output panel and paste it directly into your terminal. Alternatively, use curl -u username:password https://api.example.com and curl will encode it for you.
Basic Auth encodes a username/password pair. Bearer tokens (used in OAuth 2.0/JWT) are opaque tokens that represent an authenticated session. Bearer tokens are generally preferred for modern APIs.
HTTP Basic Authentication is one of the simplest and oldest authentication schemes defined in the HTTP specification. It transmits credentials — a username and password — as a Base64-encoded string in the Authorization request header. The format is straightforward: the username and password are concatenated with a colon separator (username:password), the resulting string is Base64-encoded, and the encoded value is sent in the header prefixed with the word Basic followed by a space.
For example, if your username is admin and your password is password123, the raw string is admin:password123. Base64-encoding that produces YWRtaW46cGFzc3dvcmQxMjM=, and the complete Authorization header becomes: Authorization: Basic YWRtaW46cGFzc3dvcmQxMjM=.
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Base64 is a binary-to-text encoding scheme that represents binary data using a set of 64 printable ASCII characters. It is not encryption — it is purely an encoding mechanism used to ensure that the credential string can be safely transmitted as part of an HTTP header without character encoding issues.
The encoding process takes groups of 3 bytes (24 bits) and converts them into 4 Base64 characters (6 bits each). If the input length is not a multiple of 3, padding characters (=) are added to make it so. This is why you often see one or two equals signs at the end of a Base64-encoded value.
Because Base64 is trivially reversible — anyone who intercepts the header can instantly decode it to retrieve the plaintext credentials — HTTP Basic Auth must always be used over HTTPS (TLS/SSL) in any real-world application.
Basic Auth remains widely used in specific scenarios despite being one of the older authentication mechanisms. It is particularly common for internal APIs, server-to-server communication, and simple services where a full OAuth 2.0 flow would be overkill. Common use cases include:
.htpasswd files to protect directories and endpoints, especially for staging environments.Once you have generated your Authorization header using this tool, you can use it in any HTTP client:
curl: Pass the header directly with the -H flag, or use curl's built-in -u username:password shorthand which constructs the header automatically.
JavaScript fetch API: Add the header to the headers object in your fetch options: headers: { 'Authorization': 'Basic <encoded>' }.
Python requests: Use the auth parameter with a tuple: requests.get(url, auth=('username', 'password')). The library handles encoding for you.
Postman / Insomnia: Select "Basic Auth" from the Authorization tab and enter your username and password. The tool builds the header automatically.
While convenient, Basic Auth has real security implications you should understand before deploying it in production:
If you need to verify what credentials are encoded in an existing Authorization header, you can reverse the process: take the string after "Basic ", Base64-decode it, and split on the first colon. The part before the colon is the username; everything after is the password. Our Base64 Encode/Decode tool can help with decoding if needed.