How it works
Paste or type your text in the box and JWT Header Decoder transforms it instantly — no button to press. The result updates live as you edit, runs entirely in your browser, and you can copy the output with one click.
Examples
- “eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxMjMifQ.abc” → “{ ⏎ "alg": "HS256" ⏎ }”
Frequently asked questions
How do I use the JWT Header Decoder?
Paste or type your text into the input box. JWT Header Decoder processes it live and shows the result immediately — then just copy it. There is no limit on how much text you can process.
Is my data private?
Yes. The JWT Header Decoder runs entirely in your browser. Nothing you enter is uploaded, saved to a server, or shared — it never leaves your device.
Is the JWT Header Decoder free?
Yes, it is completely free with no sign-up, no limits and no watermarks. Like every tool on developer tools and the rest of the platform, you can use it as often as you like.
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