What Is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that converts data into a string of ASCII characters. It's one of the most widely used encoding formats in software development, and you'll encounter it constantly when working with:

• APIs and HTTP headers — Basic authentication credentials are Base64-encoded before being sent in the `Authorization` header.
• Email attachments — MIME protocol uses Base64 to encode binary data like images and files in email bodies.
• Data URIs — Embedding images or fonts directly in HTML/CSS using `data:image/png;base64,...`.
• JWT Tokens — JSON Web Tokens use Base64URL encoding for their header and payload sections.
• Storing binary data in JSON — JSON doesn't support raw binary, so binary data is often Base64-encoded first.

How to Use the Base64 Encoder?

1. Paste your original string into the input box above.
2. Press the "Encode" button to Encode the text.
3. Click to copy the result to your clipboard.

Base64 Encoding — Key Facts

• Base64 encodes every 3 bytes of input into 4 ASCII characters.
• Encoded output is approximately 33% larger than the original input.
• The Base64 character set uses A–Z, a–z, 0–9, `+`, `/`, and `=` for padding.
• For URL-safe encoding, use Base64URL which replaces `+` with `-` and `/` with `_`.