JWT Decoder
📦 JWT Decoder Source Code $5.99
Get the complete, ready‑to‑deploy HTML file with all styling and logic. This is the exact code powering the demo above — no dependencies, fully offline, and 100% client‑side. Perfect for your portfolio, client projects, or resale. One-time purchase, lifetime access.
What is a JWT Decoder?
A JWT decoder takes an encoded JSON Web Token and extracts the header and payload into readable JSON. Developers use this tool to quickly inspect claims like user ID, expiration time, and issuer without needing to write code. It also checks whether the token has expired based on the exp claim. Because all decoding runs locally in your browser, sensitive tokens never leave your machine.
How to Use
- Paste your JWT into the input panel. The token must be in the standard three‑part format:
header.payload.signature. - Click "Decode" to parse the token. The header and payload will be displayed as formatted JSON in the output panel.
- Check the validity badge to see if the token has expired. Use the copy button to grab the payload JSON for further inspection.
Frequently Asked Questions
Is my JWT data safe?
Absolutely. All decoding is performed locally in your browser. The token is never transmitted, stored, or logged on any server. Even if it contains sensitive claims, you can safely use this tool offline.
Does this tool work offline?
Yes, completely. There are no external libraries or API calls. Save the HTML file and you'll have a fully functional JWT decoder available anytime, even without internet access.
Can it verify the signature?
No, this tool does not verify the cryptographic signature. It only decodes the header and payload. Signature verification requires the secret or public key and should be performed on a server. This tool is meant for quick inspection of token contents.
Disclaimer: This tool performs all operations locally in your browser. No data is stored, transmitted, or logged.