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Decode JWT tokens and inspect header, payload, and signature instantly. Free online JSON Web Token decoder for debugging auth.
JWT Decoder is a free online security tool that works right in your browser — whatever you enter is processed locally and never sent to a server. No installation, no signup; works on both phone and desktop, ready to use instantly.
All security tools run locally without sending any data externally. Password generation, hash computation, and other sensitive operations happen entirely in your browser.
When testing security tools, sending sensitive data like passwords or tokens to a remote server defeats the purpose. We built this tool to run entirely in your browser using the Web Crypto API — your data never leaves your device.
Developers, security analysts, and system administrators who need to handle sensitive values safely. From generating test credentials to verifying hashes and tokens, this tool runs entirely in your browser so nothing confidential ever reaches a third-party server.
Yes, completely free with no signup required.
Yes, it works on mobile browsers with touch support.
Security
Completely safe. All checks run locally in your browser without sending any requests or data externally.
ToolPure supports MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hash algorithms. All hashing is performed locally using the Web Crypto API, ensuring your data never leaves your browser.
Yes, you can decode JWT tokens to inspect header and payload, and generate new JWT tokens with custom claims. The tool supports HS256, HS384, and HS512 signing algorithms.
Yes, password generation uses the Web Crypto API getRandomValues() function, which provides cryptographically secure random numbers. Generated passwords are not stored or transmitted anywhere.
Yes. JWT Decoder is a pure front-end tool: whatever you type or paste is processed only in your browser's memory and never sent to a server. It disappears as soon as you refresh or close the page.
🔒 Privacy & Security：All processing happens locally in your browser. Files are never uploaded or stored.
🔒 Privacy: All processing happens locally in your browser. Your files and data never leave your device — no upload, no server, no tracking.