Base64 Encoder & Decoder

Base64 turns binary data into copy-safe ASCII text, following RFC 4648. It is used to inline images in CSS/HTML (data: URIs), in email attachments, and in API payloads.

How it works

Every 3 bytes (24 bits) map to 4 characters from a 64-symbol alphabet. When the length is not a multiple of 3, the output is padded with =. The result is roughly 133% of the original size.

Example

Hello, World!  ->  SGVsbG8sIFdvcmxkIQ==

URL-safe variant

URL-safe replaces + with - and / with _, and drops the = padding. It is used in URLs, file names, and JWT segments.

Notes

• Encoding handles UTF-8 correctly (e.g. emoji and non-Latin scripts).
• Use Upload file to encode binary data.
• Base64 is not encryption — anyone can decode it.