Decode a JSON Web Token to inspect its header and payload, with optional HMAC/RSA signature verification.
Signature verification is optional — paste a secret (HS256/384/512) or PEM public key (RS256/384/512) only if you want to confirm the token is genuine, not just read its contents.
Not every barcode is interchangeable — a retail scanner expects a specific format, and picking the wrong one means a code that simply won't scan at checkout.
Base64 output looks scrambled, which is exactly why people mistake it for security. It isn't — it's encoding, not encryption, and the difference matters.
A UUID looks like random noise, but the format is precise, and the odds of ever generating a duplicate are so small the math is almost more interesting than the ID itself.