Developer · free
JWT Generator
Build your own JWT with a custom header, payload and an HMAC secret to produce a valid signed token for local testing.
Uses HMAC-SHA256 with a pure-JS implementation — signing happens locally.
About the JWT Generator
Build your own JWT with a custom header, payload and an HMAC secret to produce a valid signed token for local testing.
Everything runs in your browser — nothing is uploaded.
How to use the JWT Generator
- Step 1Paste your input into the field.
- Step 2Press the button to transform it.
- Step 3Copy or download the result.
When people reach for this tool
Produce a token for a test suite
A signed token built with a throwaway secret is enough to exercise your own auth code.
See the shape of a real token
Generating one by hand makes the three-part structure obvious before you depend on a library.
Recreate the exact token that failed
Rebuilding the same header, payload and secret gives you a repeatable failing case.
Practical tips
- HMAC signing needs the same secret on both sides. A token signed with one secret will never verify with another.
- Keep test secrets out of real environments — a token minted with a development secret must never be accepted in production.
What you get
- One-click transforms
- Local processing, nothing uploaded
- Free and unlimited
JWT Generator — FAQ
Which algorithm is supported?
HS256 (HMAC-SHA256) with any secret. The header and payload can be adjusted freely.
Does this create a valid production token?
It creates a correctly structured, signed token for testing. It is not a substitute for a proper identity provider, and it does not verify anything about the person holding it.
What algorithm is used?
HMAC, which means the same secret both signs and verifies. The header records the algorithm so the verifier knows what to use.
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