JSON Base64 Encode & Decode
- UTF-8 safe
- base64url
- Nothing uploaded
UTF-8 safe base64 in both directions, including the URL-safe alphabet.
Paste input on the left to see result.
Everything runs in your browser — nothing is uploaded.
About base64
Base64 encodes JSON as opaque text that survives URLs, headers and QR codes. JSONic encodes and decodes both the standard and URL-safe alphabets and handles the full Unicode range, unlike encoders built on btoa alone, which throw on any character above U+00FF.
Base64 is how JSON travels through places that only accept opaque text: URL parameters, headers, QR codes, embedded config. This encodes and decodes both the standard and URL-safe alphabets, and handles the whole Unicode range correctly — btoa alone throws on any character above U+00FF, which is why so many hand-rolled encoders break on the first emoji or accented name.
Questions
What is base64url and when do I need it?
A variant that replaces + and / with - and _ and drops the = padding, so the result is safe in URLs and filenames. JWTs use it. Decoding here accepts either alphabet automatically.
Why do other tools fail on my JSON?
They call btoa directly, which only accepts characters up to U+00FF and throws on anything else. This encodes to UTF-8 bytes first, so any valid string works.
Is base64 a form of encryption?
No. It is an encoding, fully reversible by anyone. It hides nothing — never use it to protect a secret.