Base64 Encoder & Decoder
This looks like a JWT. Its header and payload are decoded below. The signature is not verified.
Runs entirely in your browser. Your data is never uploaded.
What is Base64?
Base64 is a way to represent binary data using 64 printable ASCII characters, so it can travel through systems built for text: email (MIME), JSON, HTML data URIs, HTTP Basic authentication headers and JWTs. It is defined in RFC 4648. It is not encryption: anyone can decode it.
When to use Base64
- Embedding small images in HTML/CSS
- Sending binary in JSON
- Basic auth headers
- Email attachments
Avoid it for large files: it adds about 33% to the size.
How Base64 encoding works
Base64 splits every 3 bytes of input into four 6-bit values and maps each one to a character from a 64-character alphabet (A–Z, a–z, 0–9, + and /), adding = padding when the input length is not a multiple of 3. See the full explanation on the Base64 encode page.