Decode Base64 JWT Payload — Free
Decode Base64 JWT payload — free, online, no upload, no signup, runs entirely in your browser. Paste any JWT (header.payload.signature) and instantly see the decoded JSON for both header and payload, including standard claims like exp, iat, sub, and aud. The tool flags expired tokens and shows the algorithm used. Critical: decoding does NOT verify the signature — never trust an unverified JWT in production code. Use this for debugging and inspection only. All decoding happens locally so even production tokens with secrets stay safe.
How to decode base64 jwt payload
- Paste your input (JSON, JWT, CSV, or other text) into the tool above.
- Choose the format/option you need — everything is computed in your browser.
- Copy the result with one click, or download it as a file.
Common use cases
- Debugging API responses and inspecting JWT payloads
- Pretty-printing minified JSON copied from network tabs or logs
- Converting between data formats (CSV ↔ JSON, JSON ↔ YAML)
- Validating syntax before pasting into config files
- Sharing readable snippets with teammates in pull requests
Frequently asked questions
Does decoding verify the signature?
No — decoding only Base64-decodes the payload. Verification requires the signing key, which this tool intentionally does not handle.
Is it safe to paste production JWTs here?
Yes — decoding runs entirely in your browser. The token is never uploaded.
How do I check if a token is expired?
The decoder shows the exp claim as a human-readable date and highlights expired tokens in red.
Can it decode encrypted JWEs?
No — only signed JWTs (JWS). Encrypted JWEs require the decryption key.