jwt.io, built by Auth0 (now part of Okta), is the reference tool for working with JSON Web Tokens. It decodes a token into its header and payload, verifies signatures against a secret or public key across the common algorithms (HS256, RS256, ES256, EdDSA and more), generates and signs new tokens, and links out to a well-maintained directory of JWT libraries for nearly every language. Since its v2 redesign it runs entirely client-side — your token stays in the browser. If your job today is to debug or sign a JWT, it is hard to beat, and it is free with no signup. PayloadIQ is a different kind of tool: a privacy-first, browser-local JSON and API workbench that happens to include a JWT decoder among 50-plus utilities — so this comparison is less head-to-head and more about which job you are doing.
| Feature | PayloadIQ | jwt.io |
|---|---|---|
| Decode JWT header & payload | ✓ | ✓ |
| Verify JWT signature (secret/public key) | — | ✓ |
| Generate & sign new JWTs | — | ✓ |
| JWT libraries directory & handbook | — | ✓ |
| Runs in your browser (no upload) | ✓ | ✓ |
| Broader JSON tools (format, diff, tree, JSONPath) | ✓ | — |
| JSON to TypeScript / Zod / Prisma / SQL / Go | ✓ | — |
| Secret / PII scanner & schema-quality report | ✓ | — |
| Encoders, hashing, generators (base64, SHA, UUID) | ~50 tools | — |
| VS Code / Cursor extension | ✓ | Chrome only |
| Free with no signup | Free tier | ✓ |
When jwt.io is the better fit
If you need to verify a JWT's signature, sign a new token, or generate one for testing, jwt.io is the better choice — full stop. PayloadIQ's JWT utility only decodes and inspects the header and payload; it does not check signatures or sign tokens. The moment you need cryptographic verification or token generation, reach for jwt.io.
jwt.io is also the better starting point if you are learning how JWTs work or picking a library for your stack. Its introduction guide, the JWT Handbook, and the curated libraries directory (maintained by an identity company) are resources PayloadIQ simply does not offer. Auth0 also ships an official JWT Debugger Chrome extension built on jwt.io, so if you live in the browser its decoder follows you there too. For anything auth-specific, the Auth0/Okta pedigree is a real advantage.
Where PayloadIQ goes further
A JWT rarely shows up alone. PayloadIQ lets you decode the token, then immediately work the JSON payload inside it — format and validate it, explore it as a tree, diff it against another token's claims, scan it for secrets or PII, or turn its shape into TypeScript, Zod, Prisma, SQL or a dozen other targets. jwt.io stops at the token; PayloadIQ keeps going with the data inside it.
Beyond JWTs, PayloadIQ is a whole workbench: roughly 50 single-purpose browser-local utilities (formatters, JSONPath, base64/URL/HTML encoders, WebCrypto hashing, UUID/password/QR generators, regex, converters, file-to-Markdown) plus a payload playground, a Chrome extension, and — unlike jwt.io — a VS Code/Cursor extension that brings the tools into your editor. Like jwt.io's decoder, none of your pasted data is uploaded; it all runs in your browser.
The short version
Use jwt.io when the task is the token itself — verifying a signature, signing or generating a JWT, or learning the standard; nothing here matches it for that. Use PayloadIQ when you want to decode a JWT and then do real work on the JSON inside it, alongside 50-plus other browser-local tools. They overlap on decoding and on keeping your data local, and diverge everywhere else.