Paste one compact JWT
The isolated capsule has no network permission.
Private developer utility
Decode JWT structure without uploading the token
JWTLens separates a compact token, decodes its header and payload, preserves exact JSON number text and converts supported NumericDate claims to UTC. Every result stays marked as unverified because decoding cannot establish trust.
No account · no upload · no signature claim · no result URL
Three explicit steps
Paste, decode, verify elsewhere
Decode strict structure
Malformed encoding, UTF-8, JSON and duplicate keys are rejected.
Verify before trusting
Use the receiving service's JOSE policy and trusted keys.
For controlled debugging
Inspect representation, never authorize
- Compare claim names and nesting in a test token against an API contract.
- Read exact large numeric identifiers without JavaScript rounding them during formatting.
- Convert exact exp, nbf and iat seconds into fixed UTC timestamps for manual comparison.
Private by construction
Inspect the structure in this browser
Use a non-production fixture when possible, then verify the original token in its intended service before relying on it.