Encoding and decoding
JWT Decoder
Read token claims while keeping the difference between decoding and verification visible.
Processed locally. Your input and output are never uploaded.
Tool overview
Decoding versus verifying a token
JWT Decoder splits a token into header, payload, and signature segments, decodes Base64URL JSON, reports common claims, and warns that signature trust is not checked.
Read token claims while debugging
- Clean pasted work data before another tool uses it
- Inspect a browser-local conversion before copying it
- Prepare examples for documentation or support notes
Paste a token and inspect decoded sections
- Paste or type the input.
- Choose the processing options that match the source.
- Run the tool and review the result.
- Copy or download the output.
Header, payload, timestamps, and signature segment
- Options are explicit so destructive behavior is visible before processing.
- Input and output stay in separate editors.
- Examples load realistic settings for the tool.
Inspect a token with an expiration claim
Before
eyJhbGciOiJub25lIiwidHlwIjoiSldUIn0.eyJzdWIiOiIxMjMiLCJleHAiOjQxMDI0NDQ4MDB9.
After
Warning: Decoding a JWT does not verify its signature or prove that the token is trustworthy.
Header
{
"alg": "none",
"typ": "JWT"
}
Payload
{
"sub": "123",
"exp": 4102444800
}
Algorithm: none
Type: JWT
Issuer: not specified
Subject: 123
Audience: not specified
Issued at: not specified
Not before: not specified
Expires: 2100-01-01T00:00:00.000Z
Expiration state: Active by timestamp
Raw signature segment: Decoding is not signature verification
- Decoding a JWT does not verify its signature.
- Invalid Base64URL or non-JSON segments are rejected.
- Sensitive tokens should still be cleared after inspection.
Browse all encoding and decoding tools →
Questions
JWT Decoder FAQ
Does JWT Decoder upload my input?
No. Processed locally. Your input and output are never uploaded.
Can JWT Decoder change meaning?
Only options described on the page are applied; review output before using it in a workflow.
What happens with invalid input?
The tool reports an error and leaves the source text available in the input editor.