Best Free JWT Decoder
Decode a JWT header and payload in your browser, with exp/iat as dates — no upload, no signature verification.
100% free
No signup
No watermark
Files processed in memory, never stored
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How it works
- Paste the token. Drop a JWT (the eyJ… string) into the input box.
- Decode it. Click Decode to pretty-print the header and payload as JSON.
- Read the claims. Check exp/iat as human dates. Everything stays in your browser; the signature is not verified.
About this tool
Paste a JSON Web Token and instantly read what is inside it. The decoder splits the token on its dots, Base64url-decodes the header and payload, and pretty-prints both as JSON. Timestamp claims like iat, nbf and exp are shown as human-readable dates, with exp flagged as expired or valid. Crucially, this tool only DECODES the token locally to inspect it — it does NOT verify the signature and nothing is ever sent to a server, so it is safe to paste a token while debugging auth. The signature segment is shown as-is, clearly marked unverified.
What people use it for
- Inspect the claims inside an auth token while debugging
- Check a token expiry (exp) and issued-at (iat) dates
- See which algorithm and headers a JWT uses
- Read a custom payload field without a server round-trip
Frequently asked questions
No. It only decodes the token to show what is inside — it does not check the signature against a key. Treat a decoded payload as untrusted until your backend verifies it.
No. The split and Base64url decode happen entirely in your browser, so the token is never uploaded. That makes it safe to paste a real token while debugging.
The exp, iat and nbf claims are Unix timestamps; the tool converts them to human dates and flags whether exp is in the past (expired) or still valid.
The third dot-separated segment, shown exactly as-is and labelled not verified. It is there for reference — the tool does not validate it.
A JWT must be three Base64url parts separated by dots. If a part is missing or is not valid Base64url JSON, the decoder flags it instead of guessing.
Completely free, no account, no limits — a client-side tool with nothing to meter.
Yes. It runs in your browser, so JWT Decoder works on phones and tablets as well as desktop — there is no app to install.
Usually just a few seconds for a typical file — JWT Decoder starts working the moment you give it your input.
Your input is decoded in your browser; never uploaded or verified, so nothing is left behind once you have your result.
Casual use is unlimited, under a generous fair-use cap that keeps it fast for everyone.