JWT Decoder
Decode JSON Web Tokens instantly in your browser with zero server communication. Paste any JWT to inspect the decoded header (algorithm, token type), payload claims (subject, issuer, expiry, custom fields), and expiry status. Safe for development and staging tokens — everything runs locally.
How to Use the JWT Decoder
- 1
Copy your JWT
Copy the full JWT string — it looks like three Base64-encoded segments separated by dots (xxxxx.yyyyy.zzzzz).
- 2
Paste it in
Paste the token into the input field. The decoded header and payload appear instantly.
- 3
Inspect the claims
Review the payload claims: sub (subject), iss (issuer), exp (expiry), iat (issued at), and any custom claims.
- 4
Check expiry
The exp claim is shown as a human-readable date and time so you can verify whether the token is still valid.
Key Features
Client-Side Only
Token never transmitted — safe for development and staging tokens with sensitive claims.
All Claims Visible
Displays all registered and custom payload claims in a readable format.
Expiry Check
Shows the exp claim as a human-readable date and indicates whether the token is expired.
Pro Tips
Remember: decoding is not the same as verification. This tool shows you the claims but cannot confirm the token was legitimately issued.
For production tokens with sensitive user data, prefer a command-line tool or your IDE rather than any online decoder.
The header's "alg" field tells you the signing algorithm — HS256 uses a shared secret, RS256 uses a public/private key pair.
Privacy Note
All processing in this tool runs entirely in your browser — no data is transmitted to any server. Your input is never logged, stored, or shared. This tool is free to use with no account or registration required.
Frequently Asked Questions
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Your input is processed locally in your browser and is never stored, transmitted, or shared with any server. See our Privacy Policy.