How the base64 encoder / decoder works
Base64 encodes binary or text data into an ASCII-safe string using a 64-character alphabet (A–Z, a–z, 0–9, + and /), commonly used to embed data in places that only accept plain text — like JSON payloads, URLs, or email attachments.
Step-by-step guide
- Choose Encode or Decode.
- Paste your text or Base64 string.
- Read the result instantly, and use Copy Result to grab it.
Common uses
- Embedding small images directly in CSS or HTML as data URIs
- Encoding credentials for HTTP Basic Authentication headers
- Safely including binary data inside JSON or XML
Frequently asked questions
No — Base64 is an encoding scheme, not encryption. It's fully reversible by anyone with no key required, so it should never be used to protect sensitive data.
Base64 represents every 3 bytes of input as 4 output characters, so encoded output is roughly 33% larger than the original.
No — encoding and decoding both happen entirely in your browser using JavaScript's built-in Base64 functions.