JWT Decoder
JWT Decoder Online – Decode JSON Web Tokens
About JWT Decoder
A JSON Web Token (JWT) decoder splits encoded authorization tokens into readable JSON structures, separating header algorithms, payload claims, and signatures.
How It Works
The decoder reads the three dot-separated Base64Url parts of a token, parses them in memory, and formats the claims with syntax highlighting, converting timestamps to relative times.
How to Use JWT Decoder
- Paste your encoded JSON Web Token (JWT) string into the input panel.
- Inspect the decoded JSON headers and claims generated in the target panes.
- Hover over timestamp fields to see exact expiration dates and creation metrics.
FAQ
Does this verify the signature?
No. Signature verification requires the issuer's secret or public key, which we deliberately never accept. Decoding is local and key-free.
Is it safe to paste production tokens?
The token never leaves your browser. That said, treat live tokens like passwords — prefer to decode short-lived test tokens whenever possible.
Under the hood
Splits the compact serialization on `.`, Base64URL-decodes each segment via a streaming Uint8Array codec, and renders the JSON with a syntax tree highlighter. Standard claims (`iat`, `exp`, `nbf`) are tagged with relative-time annotations.
Engineered by HaorGrix