CodesBeautify

Base64 to JSON

Decode a Base64 payload into JSON, validate it, and print it with the indentation you prefer.

Base64
JSON
Runs locally in your browser

About the Base64 to JSON

Queue messages, webhook envelopes and JWT payloads all arrive as Base64 wrapping a JSON document. Two steps stand between you and the data: decoding the string, then making the one line result readable. This tool does both and validates the JSON on the way through, so you learn immediately whether the payload is intact or truncated.

Parsing is strict. Comments, trailing commas and single quoted keys are rejected, and the message names the line and column where the problem sits inside the decoded text. That distinction matters when debugging: an error here tells you the Base64 was fine and the producer emitted malformed JSON, while a Base64 error tells you the string itself was mangled in transit.

The status line summarises what came back, such as an object with nine keys or an array of forty entries, which is a fast way to confirm you decoded the right message. Indentation can be two spaces, four spaces, a tab, or minified when you want to feed the result to something else. Kafka and SQS payloads with awkward line breaks inside the Base64 are handled, since whitespace is stripped before decoding.

For a full tree view of a large result, paste it into JSON Viewer, and use JWT Decoder when the input is a complete three part token.

How to use

  1. Paste the Base64 payload, including any URL-safe characters from a token.
  2. Choose the Indent style you want to read the result in.
  3. Check the status line for the shape of the data, then copy or download the JSON.

Common questions

Can I paste a whole JWT?
No. Paste only the middle segment between the dots, or use JWT Decoder, which splits the header, payload and signature for you.
The Base64 decoded but the JSON is rejected. What now?
The producer sent malformed JSON. The error names the line and column in the decoded text so you can see exactly what broke.
Are line breaks inside the Base64 a problem?
No. Whitespace is removed before decoding, so wrapped payloads from log files work as pasted.
Does the key order change?
No. Keys are re-printed in the order they appear in the decoded document.