Free Online Developer Tools – ULID, UUID, NanoID, CUID, Snowflake ID, JWT Decoder, Base64, JSON Formatter & More

ULID Generator

Generate Universally Unique Lexicographically Sortable Identifiers with high performance

193,000,000
ULIDs Generated
1,500
ULIDs/Second
150
Active Users

JWT Decoder Online

Decode any JSON Web Token (JWT) instantly. View the header algorithm, payload claims (exp, iat, sub), and validate structure — all in your browser, no data sent to any server.

JWT Decoder & Debugger

Parse JSON Web Tokens, inspect claims, and scan for common security vulnerabilities

Real-time Security Warnings
Paste a JWT token to scan its header and payload for known security weaknesses.
HS256 Secret Verification
Paste JWT and enter secret to verify
Header (Algorithm & Token Type)
// Paste a token to inspect...
Payload (Claims & Metadata)
// Paste a token to inspect...

What is a JWT Token?

A JSON Web Token (JWT) is a compact, URL-safe token format used for authentication and information exchange. It consists of three Base64URL-encoded parts separated by dots: header.payload.signature.

How to Decode a JWT

  1. Paste your JWT token into the input field above
  2. The decoder instantly splits and Base64URL-decodes each part
  3. View header (algorithm, token type), payload (claims), and signature
  4. Check expiry time (exp) and issued-at (iat) in human-readable format

Common JWT Claims

iss

Issuer

sub

Subject

aud

Audience

exp

Expiration time

iat

Issued at

jti

JWT ID

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