What is the difference between Base64 and Base64URL?
Base64URL replaces + and / with - and _ so encoded values are safe inside URLs and tokens. This tool can decode both forms and normalize padding when strict mode is off.
Base64 to JSON Converter
Decode Base64, Base64URL, JWT segments, and JSON data URIs into readable JSON, searchable tree output, raw text, or byte-safe inspection views with local-only browser processing.
Decode Base64, Base64URL, JWT segments, and JSON data URIs into readable JSON, searchable tree output, raw text, or byte-safe inspection views without leaving the browser.
Live status
Ready to decode Base64 into JSON or raw text.
Stage: validate
Worker threshold: 300.0 KB
Input Source
Paste Base64 directly, upload a file, or load a realistic sample.
Simple JSON object encoded as regular Base64.
Detected: standardInput: 52 BAuto decode: on
Live decode is active for this input size.Supports Base64, Base64URL, JWT, and data URIs
Base64 Input
Input Source
Paste Base64 directly, upload a file, or load a realistic sample.
Simple JSON object encoded as regular Base64.
Detected: standardInput: 52 BAuto decode: on
Live decode is active for this input size.Supports Base64, Base64URL, JWT, and data URIs
Decoded Output
Decode Result
The tool prefers JSON automatically, adds binary-safe fallback views, and keeps the normalization story visible.
Input type: standardStandard: base64Encoding: pendingJSON: not parsedBinary: noEngine: mainDelta: 0 B
All processing happens locally in your browser. No data is uploaded or stored.
Ready to decode Base64 into JSON or raw text.
Decode output appears here. JSON opens in Pretty JSON and Tree View, binary-like payloads get a safe Hex / Bytes tab, and everything keeps a full audit trail.
How to Use
- Paste a Base64 string, Base64URL value, JWT, or data URI into the input panel.
- Load a sample or upload a text file if you want to test common decoding scenarios quickly.
- Inspect Pretty JSON or Tree View when parsing succeeds, switch to Raw Output for readable text, or use Hex / Bytes for binary-heavy payloads.
- Use normalization details, JWT inspection, and Open In actions when you need deeper debugging or a quick handoff into another JSON tool.
Related Tools
Frequently Asked Questions
Why does the tool sometimes show raw text instead of JSON?
Base64 only encodes bytes. After decoding, the content might be JSON, plain text, logs, or another text payload. If the decoded text is not valid JSON, the tool keeps it available in Raw Output instead of forcing a parse error.
Can this tool decode JWT payloads?
Yes. When a full JWT is detected, the tool can inspect both the header and payload, surface common claims like exp and iat, and keep the raw signature segment visible. Signature verification is out of scope for this tool.
Why is there a Hex / Bytes view?
Some decoded payloads are not clean UTF-8 text. The Hex / Bytes view gives you a safer way to inspect binary-heavy output, control characters, or lossy text decodes without pretending that the result is normal JSON.
What does strict decoding change?
Strict mode stops the tool from repairing whitespace, missing padding, or similar issues. It is useful when you want validation to fail instead of being normalized silently.
Is my Base64 data uploaded anywhere?
No. All decoding and JSON parsing happens locally in your browser. No data is uploaded or stored.
How is this different from the Base64 Decode tool?
This tool is optimized for Base64 payloads that contain JSON — it parses, pretty-prints, and provides a tree view of the decoded JSON. The general-purpose Base64 Decode tool handles any Base64 content (text, binary, hex dumps) and is better when the encoded data is not JSON.