Base64 Encoder / Decoder
Convert text to Base64 and back, fully Unicode-safe — Chinese, emoji and other non-Latin characters survive the round trip.
What is it
Base64 turns any bytes into a safe string of 64 ASCII characters: A-Z, a-z, 0-9, plus and slash, with equals as padding. The catch: plain btoa only accepts Latin-1, so Chinese or emoji break it. This tool first encodes your text into UTF-8 bytes, then into Base64 — and decodes the same way back, so nothing gets mangled.
Notes & fun facts
Base64 is everywhere but invisible: email attachments, image data URIs in CSS, JWT tokens, authorization headers. If you ever wondered why a JSON web token looks like a wall of letters and dots, half of it is just Base64. The funny part: Base64 is not encryption — anyone can decode it in two seconds, it only exists so binary data survives systems that were designed for text.
Origin & history
Base64 comes from the PEM email encryption standard defined by the IETF in RFC 1421 in 1993, though the encoding ideas were already circulating in the late 1980s. Its base-64 alphabet was chosen so data could travel through older email gateways that mangled non-ASCII bytes. It later became part of MIME (1996) and then quietly took over the web.