Base64 Tools
Base64 ⇄ JSON Converter
Decode Base64 payloads straight to validated, pretty JSON — or encode JSON to Base64 for headers and env vars.
In short
Decode Base64 to JSON online (and encode JSON to Base64): UTF-8 safe, validated, pretty-printed output with exact error positions. Free and private.
By NaveenKumar T · Updated
Learn: What is Base64? Encoding Explained Without the Mystique
- Both directions in one tool
- UTF-8 safe en/decoding
- Validates & pretty-prints JSON
Runs entirely in your browser — nothing you paste or open here is uploaded, logged, or stored.How we handle data →
Example
Base64 to JSON: input and output
A JWT-style payload segment pasted as Base64 and decoded back into readable JSON.
eyJzdWIiOiJ1c2VyXzVmM2EiLCJuYW1lIjoiWm/DqyBSYXZlbCIsInJvbGVzIjpb
ImVkaXRvciIsImJpbGxpbmciXSwiZXhwIjoxNzg5NjAzMjAwfQ=={
"sub": "user_5f3a",
"name": "Zoë Ravel",
"roles": [
"editor",
"billing"
],
"exp": 1789603200
}The line break inside the Base64 was ignored, the ë came back intact because the bytes are decoded as UTF-8, and the compact one-line document was pretty-printed with two-space indentation.
Learn more
Base64 and JSON in practice
Base64-wrapped JSON is everywhere: JWT header and payload sections, Kubernetes secrets, webhook signatures, message-queue payloads, basic-auth-adjacent headers. Decoding here is one paste: the Base64 is reversed byte-for-byte (UTF-8 aware, so non-ASCII content survives), then the text is parsed and pretty-printed as JSON with precise errors if it isn't.
Encode mode goes the other way for the same use cases — your JSON validated first, then encoded compactly for an env var or header. Note that Base64 is encoding, not encryption: anyone can decode it, so it hides nothing.
Help
Frequently asked questions
Everything you need to know about the Base64 to JSON.
01How do I use Base64 to JSON?
Paste JSON and Convert to Base64-encode it (JSON → Base64 is the default mode); switch the mode to Base64 → JSON to decode a payload into validated, formatted JSON. Both directions are UTF-8 safe.
02My Base64 decodes to garbage — what went wrong?
Three usual suspects: the value is URL-safe Base64 (replace - with + and _ with / first), it's only PART of a payload (a JWT has three dot-separated sections — decode them separately), or the content was never JSON (it may be compressed or binary). The tool tells you whether the bytes were valid UTF-8 and whether the text parsed.
03What does Base64 → JSON do if the decoded text isn't valid JSON?
It stops and reports the JSON parse error with its line and column inside the decoded text, instead of showing a half-usable result. That is what you see when the payload is a plain string such as a password, a JWT signature segment, or a compressed blob: the Base64 decoded fine, the content simply was not JSON — use the plain Base64 tool for those. Whitespace and line breaks inside the Base64 are stripped before decoding, so MIME-wrapped values from emails and certificates decode without cleanup.
Keep working
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