Base64 & JWT Decoder
Encode/decode Base64 and decode JWT tokens.
READY
base64__jwt_decoder.tool
READY
Output
SGVsbG8sIFdvcmxkIQ==
// HOW IT WORKS
Base64 encodes binary data as text; a JWT is three Base64url parts (header.payload.signature). The tool encodes/decodes Base64 and decodes JWT claims — all locally.
Example
'hi' → Base64 'aGk='. A JWT's middle part decodes to its claims, e.g. { "sub": "123", "exp": 1750000000 }.
Notes
- Decoding a JWT does NOT verify it — the signature still needs the secret/public key to be trusted.
- JWT uses Base64url (- and _ instead of + and /, no padding), a variant of standard Base64.