JSON to Base64 Online.

Convert JSON to Base64 online

A JSON to Base64 tool converts valid JSON text into a Base64 string that can be copied into APIs, test fixtures, config values, data URIs, tokens, or encoded examples. Paste JSON above, choose standard Base64 or URL-safe Base64, and copy the encoded result. The converter validates JSON before encoding so broken input does not become confusing encoded output.

How to encode JSON to Base64

1. Paste JSON into the input box or load the sample.
2. Choose encoding options - standard, URL-safe, data URI, wrapping, and minify before encode.
3. Encode and copy the Base64 output or download it as a text file.

Decode Base64 to JSON on the same page

Switch to Base64 to JSON mode when you need the reverse conversion. The decoder accepts standard Base64, URL-safe Base64, wrapped Base64, and JSON data URIs, then validates the decoded text as JSON. You can pretty-print or minify the decoded JSON before copying it.

URL-safe Base64, data URIs, and line wrapping

URL-safe Base64 is useful for query strings, URL paths, and systems that do not want +, /, or padding characters. Data URI output creates a copy-ready data:application/json;base64 value. Raw Base64 can be wrapped at 64, 76, or 120 characters per line for systems that expect chunked output.

Base64 is not encryption — this matters

Worth being blunt, because people get this wrong in ways that cause real breaches. Base64 provides zero security. It is an encoding, not encryption. There is no key, and anyone can reverse it instantly:

echo "eyJwYXNzd29yZCI6ICJodW50ZXIyIn0=" | base64 -d
# {"password": "hunter2"}

Base64 makes data transport-safe, not secret. Never use it to hide passwords, tokens, or personal data — and remember that a JWT's payload is Base64, not encrypted, so anyone holding the token can read every claim inside it. If you need secrecy, encrypt.

What Base64 is genuinely for

Moving JSON through channels that mangle certain characters: a URL query parameter, an HTTP header, a cookie, an environment variable, or a data URI. Base64 reduces arbitrary text to a small alphabet of letters, digits, and two symbols that survive the trip intact.

URL-safe Base64, and why you need it

Standard Base64 uses + and /. Both have special meaning in a URL — + is often read as a space and / is a path separator — so a token pasted into a link can silently corrupt.

URL-safe Base64 substitutes - and _ instead, and usually drops the trailing padding. It is what JWTs use. If the value is going into a query string or a path, pick it.

Encode and decode in code

// Browser / Node — the TextEncoder step handles Unicode correctly
const encoded = btoa(String.fromCharCode(...new TextEncoder().encode(json)));
const decoded = new TextDecoder().decode(
  Uint8Array.from(atob(encoded), (c) => c.charCodeAt(0))
);

# Python
import base64, json
encoded = base64.b64encode(json.dumps(data).encode()).decode()
decoded = json.loads(base64.b64decode(encoded))

Plain btoa() throws on any non-Latin-1 character, which is why the TextEncoder step above exists — it is the single most common Base64 bug in JavaScript, and it only shows up the first time a user types an emoji or an accented name.

Minify JSON before Base64 encoding

Minifying before encoding removes whitespace from the JSON text first, which usually produces a shorter Base64 string. Turn minify off when you want the decoded result to preserve readable indentation. You can also use JSON Minifier, JSON Formatter, or JSON Validator before encoding. For a full walkthrough, read how to convert JSON to Base64.