How do I decode Base64 to JSON?

Paste the Base64 string and click Decode. The tool decodes the bytes back to text, then parses and pretty-prints the result as JSON so you can read it. If the decoded text is not valid JSON, it still shows the raw decoded output with a warning.

Can I use this to read a JWT payload?

Yes — for the claims segment. A JWT has three dot-separated parts; the middle part is Base64URL-encoded JSON. Paste that segment to inspect the claims. Note that JWT uses the URL-safe Base64 alphabet (- and _ instead of + and /); convert those characters if your token does not decode cleanly. For full token parsing, use the JWT Decoder.

Why does my decoded JSON look garbled?

Usually one of three causes: the string is Base64URL (swap - _ for + /), it is truncated or has wrong padding, or it was never JSON to begin with. The tool reports when the decoded text fails to parse as JSON so you can tell encoding errors from non-JSON data.

Does decoding handle Unicode correctly?

Yes. The decoder is UTF-8-safe, so accented characters, CJK text and emoji in the original JSON are restored exactly. The output is then re-indented for readability.

Is my data sent to a server?

No. Decoding, parsing and formatting all run in your browser. Tokens, payloads and config never leave your device.

Base64 to JSON - Decode Base64 to JSON Online Free

Base64 to JSON — decode, validate and read

Decoding Base64 back to JSON is how you read a payload that was packed for transport — a token claim, an inlined data: URI, a config blob from an environment variable, or an API response that encoded its body. This tool decodes UTF-8-safely, then parses and pretty-prints the JSON so it is readable, all in your browser.

Base64 vs Base64URL

Standard Base64 uses + and /; the URL-safe variant (used by JWTs and many APIs) uses - and _ and often drops = padding. If a token will not decode, swap those characters back. For full three-part token parsing, use the JWT Decoder.

What you get

The decoded text validated as JSON (errors flagged, not hidden).
Pretty-printed output with consistent indentation.
Correct Unicode restoration (emoji, accents, CJK).

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Free Base64 to JSON decoder — decode, validate and pretty-print

Base64 to JSON — decode, validate and read

Base64 vs Base64URL

What you get

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