JWT Decoder
Decode a JSON Web Token — view the header, payload, and time claims (iss, exp, iat, nbf). No signature verification.
Paste Your JWT Token
Note: This tool only decodes the header and payload — it does not verify the signature. Never trust a JWT's claims without server-side signature verification.
What is a JWT?
A JSON Web Token (JWT) is a compact, URL-safe token format. It has three parts separated by dots: Header (algorithm), Payload (claims), and Signature. The header and payload are Base64url-encoded JSON.
Signature verification
This tool decodes the header and payload only. It does not verify the signature. In production, always verify the JWT signature server-side using the issuer's public key or shared secret.
Why use JWT Decoder online?
JWT Decoder in the browser saves context switching: no CLI install, no fragile one-liners, and instant feedback for teammates who do not live in the terminal. It is ideal for debugging, demos, and quick checks during code review.
Tips for best results
Work with a sample payload first, then paste production data. Keep privacy in mind: prefer local browser processing for secrets, tokens, and customer data. Bookmark this page for faster access next time.
How to use
- Paste a JWT (the three-part dotted string) into the input.
- Click Decode JWT.
- The header, payload, and time claims are displayed. Copy any section as formatted JSON.
- Review the output and use Copy to paste into your editor, ticket, or chat.
- Need another utility? Scroll to Related Tools below for JWT Decoder companions on skybin.io.
- For a deeper walkthrough, read the linked Skybin blog article at the bottom of this page.
Online tool vs terminal
| Terminal / CLI | This tool |
|---|---|
| echo "$JWT" | cut -d. -f2 | base64 -d 2>/dev/null | jq . | Paste the full JWT (header.payload.signature) |
| node -e 'const p=process.argv[1].split(".")[1];console.log(JSON.parse(Buffer.from(p,"base64url")))' "$JWT" | Click Decode JWT — header and payload appear as formatted JSON |
| Install jq, handle base64url padding, decode exp manually | See exp/iat/nbf as human-readable dates and expiry status |
Decoding runs entirely in your browser using Base64url decoding — nothing is sent to any server.
Frequently Asked Questions
- Does this verify the JWT signature?
- No. This tool only decodes — it does not verify. Never trust a JWT's claims in production without server-side signature verification.
- What is the exp claim?
- The exp (expiration time) claim is a Unix timestamp indicating when the token expires. This tool shows it as a human-readable date.
- Is this tool free to use?
- Yes. All Skybin developer tools are free with no account, API key, or usage limits.
- Does my data get sent to a server?
- No. Processing runs in your browser whenever possible. Sensitive input never leaves your device unless a tool explicitly fetches a URL you provide (e.g. OG Validator).
- Can I use this on mobile?
- Yes. The tools work in modern mobile browsers, though a desktop screen is easier for large JSON or PDF workflows.
- How is this different from desktop apps?
- There is nothing to install or update. Open a bookmarked URL and start working — ideal for quick tasks during development or support calls.
- Are there keyboard shortcuts?
- Most tools support standard paste (Ctrl+V / Cmd+V) and select-all in text areas. Copy buttons provide one-click output.
- Does Skybin store my history?
- No. We do not log tool inputs or outputs. Refreshing the page clears in-memory state unless the tool encodes state in the URL.
- What is the difference between JWT and a session cookie?
- A session cookie is an opaque ID stored server-side or in a database. A JWT is self-contained: the server can read claims from the token after verifying the signature, which suits stateless APIs and microservices.
- Can I decode refresh tokens here?
- Yes, if they are JWTs. Treat refresh tokens like passwords — decode only in a secure environment, never share them in tickets or screen shares, and never log them in analytics.
- Why does decoding fail for my token?
- Common causes: extra quotes or Bearer prefix left on the string, truncated copy/paste, or a JWE (encrypted JWT) which requires a key to decrypt before you can read claims.
- Where can I learn more about JWT security?
- See the Skybin blog guide linked below for decoding walkthroughs, exp/iat checks, and when to verify signatures on the server.