JWT Validator

Decode any JSON Web Token, inspect its claims with live expiry status, and verify HS256 signatures - all locally in your browser.

What is a JWT?

A JSON Web Token is a compact, signed credential that web apps use to prove who you are after login. It has three Base64URL parts separated by dots: a header naming the signing algorithm, a payload carrying claims like your user ID and role, and a cryptographic signature. Because the payload is merely encoded - not encrypted - anyone who holds the token can read it, which is exactly what this decoder shows you.

Why decode a JWT?

When an API returns 401 or your session dies unexpectedly, the fastest diagnosis is to look inside the token: is the exp claim in the past? Does the aud match the service you are calling? Is the role claim what the backend expects? Developers in Nepal building dashboards for banks, e-commerce sites, and government portals all debug auth flows this way, and pasting the token here beats squinting at console.log output.

Reading the standard claims

The tool highlights the registered claims defined by RFC 7519: exp (expiry), iat (issued at), nbf (not before), iss (issuer), aud (audience), sub (subject), and jti (unique ID). Timestamps render in your local timezone with a live expired/valid badge so you can see at a glance whether time skew between server and client is causing your problem.

Verifying HS256 signatures

A signature proves the token was issued by someone holding the secret key. If your app uses HMAC signing (HS256, HS384, HS512), paste the shared secret below the token and this tool recomputes the signature locally using the Web Crypto API and compares it byte by byte. RS256 and ES256 need a public key in JWK format, which browsers cannot yet import generically here - for those, verify on your backend.

The danger of alg: none

If the header says "alg": "none", the token is unsigned and anyone can forge one. Some old libraries accepted such tokens unless explicitly configured otherwise, leading to serious breaches. This tool flags unsigned tokens loudly so you never ship one by accident.

Privacy and security

Decoding happens entirely in your browser - tokens and secrets are never sent to any server, logged, or stored. That said, treat every token as sensitive: it grants access until it expires, so avoid pasting production tokens anywhere you do not trust.

100%

Free, always

Sign-up needed

Unlimited

Uses

Private

Runs in browser

Offline

Works without net

Made for JWT Validator in Nepal

Developers inspecting and verifying JSON Web Tokens during API work.

Backend devs

Debug auth flows in Kathmandu startups.

CS students

Learn token-based security hands-on.

Freelancers

Integrate OAuth and verify tokens for clients.

Security testers

Inspect claims during penetration tests.

Mobile devs

Confirm token payloads in app backends.

API engineers

Validate tokens before shipping endpoints.

What is a JWT validator, and how does this free Nepal tool work?

A JWT validator decodes a JSON Web Token and shows its header, payload and signature so you can check claims. Scolar’s tool runs in your browser: paste a token and read its parts instantly. No sign-up, no watermark, nothing uploaded.

Why it is free, with no sign-up and unlimited use

Decoding happens on your device, so tokens stay local and no account is needed. That keeps it 100% free with unlimited checks and no watermark.

How to use this tool, step by step

Paste the JWT (the three-part token string) into the box.
Read the decoded header, payload and signature.
Check expiry and claims; nothing is sent anywhere.

JWT work in Nepal

Backend devs in Kathmandu debugging auth flows, students learning token-based security, and freelancers integrating OAuth all inspect JWTs daily. Offline decoding keeps live tokens off third-party servers.

“A Nepali backend dev should not install an app just to read a JWT. Paste the token, see claims — free.”

JWT checks done free in Nepal

I decode auth tokens here while debugging — free, no signup.

BO Bibek Oli Backend developer

Finally understood JWT claims thanks to this. Free and private.

NT Nisha Thapa CS student

I verify client OAuth tokens here. Runs offline, no cost.

RK Rameshwor KC Freelancer

How it works

Paste your JWT - header and payload decode instantly with no network request.

Check the claims panel for live expiry status and standard fields like iss, aud and sub.

For HS256/384/512 tokens, paste the shared secret to verify the signature locally.

Why use this tool?

Timestamps convert to your local timezone with a live Expired / Valid badge.
Unsigned (alg: none) tokens are flagged loudly so they never reach production.
Tokens and secrets stay in your browser - nothing is uploaded, logged, or stored.

Frequently asked questions

Is my JWT safe to paste here?

The tool runs entirely in your browser - nothing is uploaded or logged. Still, a valid token grants access to whoever holds it, so prefer test tokens over production ones.

Can this tool verify RS256 tokens?

Signature verification is supported for HMAC algorithms (HS256, HS384, HS512) using your shared secret. RS256 and ES256 require public-key infrastructure, so verify those on your backend.

What does the exp claim mean?

exp is the Unix timestamp after which the token must be rejected. The tool converts it to your local time and shows a live expired or valid badge.

Why can I read the payload if it is signed?

Signing proves integrity, not secrecy. The payload is plain Base64URL encoding, readable by anyone with the token. Use JWE encryption if you need confidentiality.

What should I do if my token is expired?

Expired tokens cannot be renewed - request a fresh one from your auth server, usually by calling the refresh-token endpoint your API provides.

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