JWT Decoder Online — Decode JWT Tokens Instantly & For Free
Decode and inspect JWT tokens (read-only).
Note: This tool only decodes JWTs. It does not verify signatures. Never trust a JWT without proper server-side verification.
Privacy first: This tool runs entirely in your browser. Your data never leaves your device.
Paste any JSON Web Token and instantly decode its header, payload, and signature into readable JSON. Inspect claims like expiry (exp), issued-at (iat), and subject (sub) without writing any code. Decoding is done entirely in your browser — your token is never transmitted anywhere.
How to Use JWT Decoder
- Paste your JWT: Copy a JWT token from your application, API response, or browser DevTools and paste it into the input field.
- View the decoded parts: The header, payload, and signature are shown in separate, formatted JSON panels.
- Inspect the claims: Review claims such as expiry time, issuer, audience, and any custom fields.
Features
- Decodes the header, payload, and signature of any JWT
- Displays decoded claims as formatted, readable JSON
- Shows human-readable expiry and issued-at dates
- Read-only — does not verify or sign tokens
- Runs entirely in your browser — token never leaves your device
- Free with no account required
Common Use Cases
Backend and frontend developers use JWT decoders constantly during development to inspect authentication tokens returned by OAuth providers, identity services, and custom auth endpoints. It is useful for debugging authorization issues without writing throwaway code.
Frequently Asked Questions
- What is a JWT?
- A JSON Web Token (JWT) is a compact, URL-safe token format used to represent claims between two parties. It consists of three Base64URL-encoded parts: a header, a payload (claims), and a signature.
- Does this tool verify the JWT signature?
- No. This is a read-only decoder. It decodes and displays the token contents but does not validate the signature against a secret or public key.
- Is it safe to paste my JWT here?
- Decoding happens entirely in your browser — the token is never sent to any server. However, avoid pasting tokens with sensitive claims in shared or public environments.
- What JWT algorithms are supported for decoding?
- All JWTs use the same Base64URL encoding for the header and payload regardless of algorithm (HS256, RS256, etc.), so decoding is supported for any JWT.