ToolNest

🔍 JWT Decoder

Decode JWT tokens instantly — view the header and payload as formatted JSON and check expiry at a glance. Decoding happens 100% in your browser; your token is never sent anywhere (unlike some online decoders).

🔒 100% Private — no uploads ⚡ Instant — works offline 💸 Free forever — no sign-up

Header

 
 
 
Payload
 
 
 
 
 
   
 
 
How to use the JWT Decoder
 
     
  1.  1 Paste your JWT (the xxxxx.yyyyy.zzzzz string). 
  2.  2 The header and payload decode automatically as you paste. 
  3.  3 Check the expiry banner — expired tokens are flagged in red. 
    4.  
 
 
 
Frequently asked questions
 
 
 Is it safe to paste a real token here? 
This tool decodes locally in your browser — the token is never transmitted. Still, best practice is to treat production tokens carefully and rotate any token you suspect was exposed.
 
 Does this verify the JWT signature? 
No — it decodes the Base64Url content only. Signature verification requires the secret or public key and should be done server-side.
 
 What are exp, iat and nbf? 
Unix-timestamp claims: exp = expiry time, iat = issued at, nbf = not valid before. This tool converts them to readable local dates automatically.
 
 Why does my token fail to decode? 
A JWT must have three dot-separated Base64Url parts. Check you copied the entire token without extra characters, quotes or "Bearer " prefix (the tool strips "Bearer " automatically).
 
 
 
 
 
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