Decode JWT claims
Decode a compact JWT header and claims without trusting its signature.
Local processing · Nothing is uploaded · 1 MB input limit
Input & settings
Ready. Enter your input to begin.
How to use this tool
Paste your source, choose the supported options, then process. Inspect or download the complete result.
Limits and behavior
Requires three Base64url segments and UTF-8 JSON header/claims. Signature verification and claim validity are explicitly not performed. Maximum total input 1 MB, output 3 MB, JSON nesting 64 levels. Processing stays in your browser worker. Input is limited to 1 MB and output to 3 MB. No input content is saved by CraftAI.
View JWT header and claim fields
Inspect the non-secret information encoded inside a compact JSON Web Token.
Does a decoded JWT prove its claims are authentic?
No. Decoding is not signature verification. Treat claims as untrusted until authenticated.
Related tools: verify jwt signature · validate json syntax