What is a JWT (JSON Web Token)?

A JSON Web Token (JWT) is a compact, URL-safe token format used for securely transmitting information between parties. It consists of three parts: a header, a payload, and a signature, each Base64Url-encoded and separated by dots.

How does the JWT Decoder work?

Paste your JWT token into the input field. The tool automatically splits it into header, payload, and signature, decodes the Base64Url-encoded parts, and displays them as readable JSON. It also shows expiration time and validates standard claims.

Does the JWT Decoder verify the signature?

This tool decodes and displays the signature but does not verify it. Signature verification requires the secret key (for HS256) or public key (for RS256), which this tool does not have access to for security reasons.

What information can I see in a decoded JWT?

The header shows the signing algorithm and token type. The payload contains claims like issuer (iss), subject (sub), expiration time (exp), and custom data. The signature is displayed but not verified.

How do I check if a JWT is expired?

The tool automatically checks the 'exp' (expiration) claim in the payload and displays whether the token is still valid or expired based on the current time.

What JWT algorithms are supported?

The decoder supports all common algorithms including HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, and ES512. The algorithm is detected from the header.

Is my JWT data secure when using this tool?

Yes, all decoding happens locally in your browser. JWTs are not sent to any server. However, be cautious with tokens containing sensitive data as they are displayed on your screen.

Is the JWT Decoder free to use?

Yes, the JWT Decoder on Easy Tools HQ is completely free and works directly in your browser with no registration required.

JWT Decoder

Decode and verify JSON Web Tokens - view header, payload, and signature

JSON Web Tokens (JWTs) are widely used for authentication and authorization in modern web applications. Our JWT Decoder helps developers debug and inspect JWTs by decoding the Base64Url-encoded header and payload into readable JSON, displaying expiration times, and detecting the signing algorithm — all securely in your browser.

How to Use the JWT Decoder

Our JWT Decoder makes it easy to inspect and debug JSON Web Tokens. Here's how to use it:

Enter your JWT – Paste your JSON Web Token into the input field on the left, or use one of the sample buttons to load example tokens.
Decode – Click "Decode JWT" or simply paste the token — the tool automatically decodes it.
View header – See the algorithm (alg) and token type (typ) used to sign the token.
View payload – Read the claims including subject (sub), expiration (exp), issued at (iat), and any custom claims.
Check expiration – The tool automatically checks if the token is expired and highlights it in the claims table.
View signature – The signature is displayed for reference (but not verified for security reasons).
Copy parts – Click "Copy" on any section to copy the decoded JSON to your clipboard.

Decode Header

Algorithm & token type

Decode Payload

Claims & expiration

Expiration Check

Auto-validation

One-Click Copy

Copy any part

Enter JWT Token

317 chars

• eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyLCJleHAiOjE5MzQ5ODI0MDAsImFkbWluIjp0cnVlLCJlbWFpbCI6ImpvaG5AZXhhbXBsZS5jb20ifQ • 5pZz8pQq9wLQZQ1J3Yq5zK0nKX0g5qZ5rZ5sZ5tZ5uZ5vZ5wZ5xZ5yZ

Header

HS256

{ "alg": "HS256", "typ": "JWT" }

Payload

Valid

{ "sub": "1234567890", "name": "John Doe", "iat": 1516239022, "exp": 1934982400, "admin": true, "email": "john@example.com" }

Subject (sub)	1234567890
Issued At (iat)	2024-01-01 12:34:56
Expiration (exp)	2031-01-01 12:34:56

Signature

HMAC-SHA256

5pZz8pQq9wLQZQ1J3Yq5zK0nKX0g5qZ5rZ5sZ5tZ5uZ5vZ5wZ5xZ5yZ

HS256 HMAC with SHA-256 (symmetric)

JSON Web Tokens (JWT) consist of three parts: Header (algorithm & type), Payload (claims), and Signature (verification). JWTs are commonly used for authentication and information exchange.

Security & Privacy Disclaimer

The JWT Decoder provided by Easy Tools HQ is for development, debugging, and educational purposes only. All decoding operations are performed locally in your browser — no token data is sent to our servers.

CRITICAL SECURITY WARNING: JWTs often contain sensitive authentication data, including:

User IDs, emails, and personal information
Session tokens and authentication credentials
API keys and authorization claims
Payment or subscription details
Internal system identifiers

NEVER paste production JWTs, authentication tokens, or tokens containing real user data into any online tool, including this one. While we process everything locally, browser extensions, compromised networks, or screen recording software could potentially expose your tokens.

Best practices:

Only use test tokens or sample data with this tool
Never paste tokens from production environments
Clear the input field after use
Use incognito/private mode for sensitive debugging
Consider using local CLI tools for production token inspection
Rotate any tokens accidentally exposed in screenshots or logs

Client-side processing: Your JWT is decoded entirely in your browser using JavaScript's built-in atob() function. We do not store, log, cache, or transmit any tokens you decode. Once you close or refresh the page, all data is permanently cleared from memory.

No signature verification: This tool only decodes JWTs—it does NOT verify signatures. Decoding does not validate that a token is authentic or untampered. Always verify tokens server-side with your secret or public key.

Last Updated: March 2026

Client-side • No server storage • Test tokens only