JWT Generator — Free Online Tool JWT Generator: free online tool with examples and documentation. Convert, generate, format, or analyze data instantly in your browser.
Use this free online JWT Generator directly in your browser. No signup required, no data leaves your device. Part of Utilier — a collection of 133+ developer utilities.
What is JWT Generator? Creates signed JSON Web Tokens with custom payloads and HMAC-SHA256 signatures. Set claims such as subject, issuer, expiration, and custom data, then sign with a secret key. A JWT consists of Base64URL-encoded header, payload, and signature sections; the signature detects tampering but does not encrypt the payload. Tokens are widely used for stateless authorization, so expiration, issuer, audience, and secure key handling are essential.
A JSON Web Token contains three Base64URL-encoded parts: a header that identifies the algorithm, a payload of claims, and a signature. The signature proves that a holder of the signing secret created the token and that its contents have not changed; it does not encrypt the payload, so claims should not contain secrets.
Why use jwt generator? Testing authentication systems requires valid JWTs. This tool lets you craft tokens with specific claims and expiration times for API testing without running your auth server.
When to use jwt generator Use when testing API authentication, mocking auth responses, creating test tokens for development, or learning JWT structure and signing.
How to use jwt generator Simple steps to use this tool effectively.
Enter input: Paste or type your input data into the input area. Supports various formats and encodings.Configure options: Select format, encoding, or other options as needed. Sensible defaults are provided for quick start.Process data: Click the convert, generate, or format button. Many tools show real-time results as you type.Review output: Check the output for correctness. Validation errors are shown if any issues are detected.Copy or export: Click copy button to clipboard or download results as a file for use in your project.Try examples: Use provided examples to understand features and learn common patterns and use cases.Key features Fast processing: Quick and accurate jwt generator operations with instant results.Input validation: Validates input format and provides helpful error messages and suggestions for fixes.Multiple formats: Supports various input and output formats for maximum compatibility and flexibility.Built-in examples: Includes common use case examples to help you get started quickly and learn.Copy & export: Easy copying to clipboard or downloading results as files for use in projects.Real-time updates: See results instantly as you type or change options. No need to click buttons.Client-side privacy: All processing happens in your browser. No data is uploaded to servers or stored.Comprehensive docs: Detailed documentation, specifications, FAQs, and troubleshooting help included.Common use cases Web development: Use jwt generator during coding, debugging, and testing web applications.API integration: Test API requests and responses, validate data formats, debug integration issues.Data conversion: Convert between different data formats, encodings, or representations as needed.Learning & education: Understand concepts through interactive examples, experimentation, and documentation.Documentation: Create clear examples and code samples for technical documentation and guides.Troubleshooting: Debug issues in development or production by validating, converting, or analyzing data.Quick prototyping: Rapidly test ideas, generate sample data, or validate approaches without writing code.Examples Generate signed JWT tokens.
Basic JWT Payload: {"sub":"user123","role":"admin"}
Secret: my-secreteyJhbGciOiJIUzI1NiJ9.eyJzdWIi...Technical reference JWT Generator specifications, standards, and technical details.
Standards compliance Follows industry standards, specifications, and best practices for compatibility and correctness. Input formats Supports common input formats used in web development, APIs, and data interchange. Output formats Provides multiple output format options for different use cases and requirements. Character encoding Handles UTF-8 and other character encodings correctly for international text support. Browser support Works in all modern browsers: Chrome, Firefox, Safari, Edge. Requires JavaScript enabled. Performance Optimized for fast processing of typical workloads. Large inputs may take longer depending on device. Security & privacy Client-side processing only. No data is uploaded to servers, stored, or transmitted externally. Accuracy Validated against test suites, specifications, and real-world examples to ensure correctness. Limitations Handles typical use cases efficiently. Extremely large inputs (megabytes) may be slower or hit browser limits. Updates Regularly updated with new features, improvements, bug fixes, and user-requested enhancements. Common mistakes to avoid Weak secrets Use long, random secrets (32+ characters). Short passwords are vulnerable to brute-force attacks against the HMAC signature.
No expiration Always include an 'exp' claim. Tokens without expiration remain valid forever if the secret is compromised.
Frequently asked questions Can I use RSA instead of HMAC? This tool supports HS256 (HMAC). For RS256 (RSA), you'd need public/private key pairs which are harder to manage in a browser tool.
Privacy and availability Runs entirely in your browser — zero server processing No signup or account required Works offline once loaded Fast, lightweight, no external dependencies Available as a browser extension for Chrome and Firefox Tags JSON JWT Security Related tools JWT Decoder — Decode a JWT's header and payload. Optionally verify an HMAC signature.Hash Generator — Compute MD5, SHA-1, SHA-256, SHA-384, SHA-512, and CRC-16 digests of text.HMAC Generator — Compute a keyed HMAC signature of a message (SHA-1/256/384/512).Base64 / Base32 / Base58 / Base85 Encoder — Encode and decode text using Base64, Base32, Base58, Base85, or ASCII85.Random String Generator — Generate random strings from selectable character sets, or special formats (hex, binary, MAC address).All developer tools JSON Beautifier & Validator — Format, minify and validate JSON. Reports the exact error location.HTML Beautifier & Minifier — Indent or minify HTML. 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