Base64 encoder / decoder
Convert text to Base64, or decode Base64 back to text. Pick the standard or URL-safe alphabet, and copy the result. Text is handled as UTF-8, so accents and emoji round-trip cleanly. Everything runs in your browser — nothing is uploaded.
What this does
Base64 represents arbitrary bytes using only 64 printable ASCII characters, so binary or non-ASCII data can travel through systems that only handle text — email bodies, JSON fields, data URIs, HTTP headers. Every three bytes become four characters, which is why Base64 is about 33% larger than the original.
Encoding treats your text as UTF-8 before encoding, so accents,
other scripts, and emoji all survive. Decoding is forgiving: it
ignores line breaks and surrounding spaces, restores missing
= padding, and accepts either alphabet — so a value copied
from a URL still decodes. The URL-safe alphabet swaps
+// for -/_, the form
used in JWTs, URLs, and filenames.