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Base64 JSON Decoder & Formatter — Decode and Pretty-Print in One Step

Paste a Base64-encoded JSON string — common in a JWT payload segment or an encoded API field — to decode and pretty-print it in a single step, instead of decoding Base64 and formatting JSON as two separate manual operations.

How to use B64 JSON Prettify

1. Paste the Base64-encoded string.
2. Read the decoded, pretty-printed JSON.
3. Copy the formatted result.

Frequently asked questions

Is this useful for inspecting a JWT payload?

Yes — a JWT's payload segment is Base64url-encoded JSON, so pasting just that segment here decodes and formats it directly.

What if the decoded content isn't valid JSON?

It reports a parse error rather than showing garbled output, so you know immediately if the Base64 content is not actually JSON.

Is my data uploaded anywhere?

No. Decoding and formatting both happen entirely in your browser.

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