JWT Encoder & Decoder Professional JSON Web Token Tools

Complete JSON Web Token toolkit with advanced security features. Create, decode, and validate JWTs using HMAC (HS256, HS384, HS512) and RSA (RS256, RS384, RS512) algorithms. Built with CryptoKit and Security framework integration for enterprise-grade token management and authentication workflows.

🔐 HMAC & RSA Algorithms

🛡️ CryptoKit Security

⚡ Real-time Validation

📥 Download DevHelper 👀 See Features

DevHelper JWT Encoder Screenshot showing JWT creation and validation interface

Advanced JWT Security Features

Everything you need for professional JSON Web Token management and authentication.

🔐

Dual Algorithm Support

Complete support for both HMAC (HS256, HS384, HS512) and RSA (RS256, RS384, RS512) algorithms with dynamic UI adaptation and algorithm-specific field management.

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CryptoKit Integration

Built with iOS CryptoKit and Security framework for enterprise-grade cryptographic operations, secure key management, and reliable digital signature verification.

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RSA Key Management

Support for PEM-formatted RSA keys with sample key auto-population, private/public key handling, and secure cryptographic operations using the Security framework.

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Real-time Detection

Automatic algorithm detection from existing JWTs with real-time validation, signature verification, and dynamic interface updates based on token content.

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Smart UI Adaptation

Interface intelligently adapts to show appropriate fields - secret keys for HMAC algorithms, RSA key pairs for RSA algorithms, ensuring optimal user experience.

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Token Analysis

Comprehensive JWT analysis including header inspection, payload decoding, signature validation, expiration checking, and claim verification.

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Payload Validation

JSON payload validation with syntax highlighting, standard claims verification (iss, sub, aud, exp, nbf, iat), and custom claims support.

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Easy Token Management

One-click token copying, sample token generation, and seamless integration with authentication workflows and API testing environments.

How to Use JWT Tools

Create and manage JSON Web Tokens securely in just a few simple steps.

Choose Algorithm

Select your preferred algorithm - HMAC for shared secrets (HS256/384/512) or RSA for public/private key pairs (RS256/384/512).

Configure Payload

Enter your JWT payload with custom claims, standard fields (iss, sub, aud, exp), and any additional data needed for your application.

Provide Keys

Input secret key for HMAC algorithms or RSA private/public keys for RSA algorithms. Use sample keys for testing or your own production keys.

Generate & Validate

Create JWT tokens or decode existing ones with automatic signature verification and payload validation for secure authentication workflows.

Perfect for These Development Tasks

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API Authentication

Generate and validate JWT tokens for API authentication, microservices communication, and secure service-to-service authentication workflows.

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User Session Management

Create user session tokens with custom claims, expiration times, and role-based access control for web and mobile application authentication.

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Single Sign-On (SSO)

Implement SSO solutions with standardized JWT tokens for enterprise authentication, identity federation, and cross-domain user verification.

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Testing & Development

Create test tokens for development environments, debug authentication issues, and validate JWT implementations in applications and services.

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Mobile App Security

Generate secure tokens for mobile app authentication, offline validation, and seamless user experience across different app sessions.

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OAuth & OpenID Connect

Create and validate tokens for OAuth 2.0 and OpenID Connect implementations, ensuring compliance with industry authentication standards.

Frequently Asked Questions

What's the difference between HMAC and RSA algorithms?

HMAC algorithms (HS256, HS384, HS512) use symmetric keys - the same secret key signs and verifies tokens. RSA algorithms (RS256, RS384, RS512) use asymmetric keys - private key signs, public key verifies, enabling distributed verification.

How secure are the cryptographic operations?

DevHelper uses iOS CryptoKit and Security framework for all cryptographic operations, providing enterprise-grade security with hardware-accelerated encryption and secure key management on supported devices.

Can I use my own RSA keys?

Yes! DevHelper supports PEM-formatted RSA keys. You can import your own private and public keys or use the provided sample keys for testing and development purposes.

Does it automatically detect JWT algorithms?

Absolutely! When you paste an existing JWT token, DevHelper automatically detects the algorithm from the header and dynamically updates the interface to show appropriate fields for validation.

Are standard JWT claims supported?

Yes, DevHelper supports all standard JWT claims including iss (issuer), sub (subject), aud (audience), exp (expiration), nbf (not before), and iat (issued at), plus custom claims.

Can I validate token expiration and timing claims?

Yes! DevHelper automatically validates timing-related claims like exp, nbf, and iat against the current time, providing clear feedback about token validity and expiration status.