JWT tools for decoding tokens and checking expiry claims

JWT problems usually come down to the visible claims: issuer, audience, subject, scopes, roles, issue time, and expiry. These tools make those values easy to inspect, while keeping the distinction clear between decoding a token and verifying a token.

Tools in this workflow

API & Auth

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JWT Decoder

Decode JWT headers and payloads, inspect claims, and check expiry fields at a glance.

API & Auth

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JWT Expiry Checker

Show whether a JWT is expired, valid, or missing expiry claims with readable timestamps.

Encoders & Decoders

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Base64 Encode / Decode

Encode plain text to Base64 or decode Base64 back to readable text with Unicode support.

Converters

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Timestamp Converter

Convert Unix seconds, Unix milliseconds, and ISO date strings with readable UTC and local output.

Related guides

JWT Decode explained

Learn how JWT decoding works, what header and payload claims mean, and what decoding does not prove.

Base64 Encode/Decode explained

A practical developer guide to Base64 encoding, decoding, common use cases, and debugging mistakes.

FAQ

Does decoding a JWT prove it is valid?

No. Decoding only shows the header and payload. Signature verification and claim validation must happen in the backend or trusted verification code.

What should I inspect first in a JWT?

Check exp, iss, aud, scopes, and roles first. Those claims explain many 401 and 403 failures during API debugging.