Outils/Décodeur JWT

Free tool 100% client-side

JWT Decoder

Decode and inspect any JWT token instantly. View header, payload, expiration status, and all claims purely in your browser. No data sent anywhere.

Whether you're debugging OAuth flows, verifying ID tokens, or just curious what's inside a JWT, this tool gives you full visibility without compromising security.

1M+Tokens decoded

180+Countries

100%Client-side

Guest

Decode any JWT
Expiration status
Copy decoded JSON
No token history
No export

Connected

All free features
Earn XP per decode
Badges & achievements
Progress tracking
Token history (10)

V+ V+

All connected features
Token history (50)
Export decoded token
Batch decode
Priority support

JWT Decoderv1.0

RFC 7519

0 characters

JSON Web Tokens (JWT) are everywhere from OAuth 2.0 and OpenID Connect to API authentication and session management. But when something goes wrong, you need to see inside the token. Our JWT decoder gives you a clear, structured view of every claim, all without sending your token anywhere.

Why we built this tool

Because existing JWT inspectors either send your token to a remote server (a security risk), lack essential features like expiration countdowns, or are cluttered with ads. We needed something that's fast, private, and comprehensive so we built it. Every decode happens locally in your browser. Zero network requests. Zero logs.

"Essential for debugging OAuth tokens. I decode JWTs daily to verify claims before implementing auth flows. The expiration check saves me from countless bugs."

Sarah K.

Backend Developer

"Finally a JWT inspector that works entirely client-side. No more pasting tokens into random websites that might log them. This is exactly what I needed."

Marcus J.

Security Engineer

"I use this to validate ID tokens from our identity provider. The human-readable dates and algorithm detection make it my go-to debugging tool."

Dr. Priya N.

DevOps Lead

Why use a JWT decoder?

If you work with authentication as a backend developer, security engineer, or DevOps specialist you will inevitably need to inspect a JWT. Maybe a user's session is failing and you need to check if the token is expired. Maybe you're implementing OAuth and want to verify the claims in an ID token. Maybe you're debugging a misconfigured identity provider.

Whatever the reason, you need a tool that shows you exactly what's inside: the algorithm used to sign it, the issuer, the subject, the audience, and most importantly, whether it's still valid. Our decoder surfaces all of this instantly, with human-readable dates and clear visual indicators for expiration status.

Key takeaways

JWTs have 3 parts: header (algorithm + type), payload (claims), and signature (verification)
exp (expiration) is the most critical claim always check it before trusting a token
alg: "none" is a known security vulnerability reject unsigned tokens
iss, sub, aud identify the token's origin, subject, and intended recipient

How to decode a JWT token

Using our decoder is straightforward. Everything happens in real-time with instant feedback.

Usage steps

Copy your JWT token from your application logs, browser dev tools, or identity provider response.

Paste it into the input area the decoder auto-detects the token and decodes it instantly. Alternatively, drag & drop a .txt or .jwt file.

Review the decoded header check the signing algorithm (alg) and token type (typ). The algorithm determines how the token was signed.

Inspect the payload claims issuer, subject, expiration, and any custom claims. The expiration status is displayed with a countdown.

Copy individual parts use the copy buttons next to the header and payload sections to grab the formatted JSON for debugging.

Volade vs other JWT decoders: full comparison

There are several JWT inspection tools available, but most either send your token to a server, lack critical features, or are cluttered by ads. We benchmarked the 7 most popular alternatives across 14 objective criteria.

Our competitive edge comes down to three things: 100% client-side operation(no token ever leaves your machine), expiration status with countdown, andcharacter-level breakdown of each JWT part. Tools like jwt.io and JWT Debugger decode tokens but don't show expiration status or part sizes. Worse, some send your token to their server for decoding a real concern for production tokens.

Volade's JWT decoder is the most private option available

With 14 features including expiration countdowns, human-readable dates, drag & drop file support, and per-part character counts our tool leads the category. And it's theonly one that guarantees your token never leaves your browser.

	jwt.io	JWT Debugger	JWT Editor
Client-side only (no server)
Auto-decode on paste
Expiration status
Human-readable dates
Character count per part
Drag & drop file
Copy decoded JSON
Algorithm detection
Offline support
No ads or tracking	Minimal	Minimal	Minimal
Claim validation hints
Token history
Export decoded token
Signature raw display

Tested July 2026. "Minimal" = feature present but limited or ad-supported.

We built this comparison so you can make an informed choice. Because when you're debugging authentication flows, the last thing you need is to worry about whether your JWT token which may contain sensitive user information has been sent to a third-party server.

Features by account tier

The JWT Decoder is free and fully functional. V+ unlocks advanced features for professional developers and security teams:

Feature	Free	V+ Premium
Decode JWT header & payload
Formatted JSON output
Expiration status & countdown
Human-readable date formatting
Character count per JWT part
Drag & drop token file
Copy decoded JSON per part
Claim validation & type detection
Algorithm recognition
Signature raw display
Token history (last 50)
Export decoded token as JSON file
Batch decode multiple tokens
Signature verification hints
Priority support

The free version covers everything you need for day-to-day JWT debugging. V+ is designed for teams that need token history, batch operations, and export capabilities.

Your token never leaves your browser

Unlike online JWT inspectors that send your token to their backend (and could log it), our tool processes everything locally. Once the page is loaded, it works fully offline. Verify in Developer Tools Network tab zero requests are made.

Understanding JWT structure and claims

A JWT consists of three Base64Url-encoded parts separated by dots. Each part serves a specific purpose and contains standardized fields. Here's a breakdown of what to look for:

Part	Content	Common fields
Header	Algorithm & token type	`alg` (HS256, RS256, ES256), `typ` (JWT)
Payload	Claims (data)	`iss`, `sub`, `aud`, `exp`, `iat`, `jti`
Signature	Cryptographic verification	HMAC or RSA/ECDSA signature bytes

The most important claim is exp (expiration). It's a Unix timestamp the number of seconds since 1970-01-01T00:00:00Z after which the token should no longer be accepted. Our tool converts this to a human-readable date and shows exactly how much time remains.

Upgrade to V+ for token history & export

Save your last 50 decoded tokens, export decoded JWTs as JSON files, and batch decode multiple tokens at once. From 7.99/month.

Discover V+ Premium

JWT security best practices

Never accept alg: "none" this turns off signature verification and is a critical vulnerability
Always validate the exp claim reject expired tokens server-side
Verify the issuer (iss) ensure the token comes from a trusted authority
Use short expiration times (15-60 minutes) and rely on refresh tokens for longer sessions
Never expose tokens in URLs use Authorization headers with the Bearer scheme
Rotate signing keys regularly especially for RS256/ES256 asymmetric algorithms

Beware of JWT injection attacks

Some implementations fail to validate the signature properly. Attackers can modify the payload and forge a new header with alg: "none". Always verify the signature server-side using a trusted library. This tool is for inspection only never rely on it for cryptographic verification.

Did you know?

2010JWT was introduced (RFC 7519 finalized in 2015)

85%of OAuth 2.0 deployments use JWTs (Okta 2025)

1KBtypical JWT size for an ID token

Questions about JWT decoding, claims, or V+ features? We've collected the most common ones below. If yours isn't listed, feel free to reach out we respond personally.

Frequently asked questions

Everything you need to know about our JWT Decoder and JSON Web Tokens in general.

JSON Web Token (JWT) is an open standard (RFC 7519) for securely transmitting information between parties as a JSON object. It consists of three parts: a header, a payload, and a signature.

V+ Premium

Debug authentication like a pro

Save token history, export decoded JWTs as JSON files, batch decode multiple tokens, and get signature verification hints. Trusted by developers at 200+ companies.

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Related resources

Last updated: July 2026. Sources: RFC 7519, IANA JWT Claims Registry, OAuth 2.0 Framework, Okta 2025 Identity Report.