Building, testing, and debugging HTTP APIs is core to modern development. These browser-based API tools give you a REST client, cURL builder, JWT utility, and HTTP playground without installing Postman or Insomnia.
What Is the JWT Builder?
JWT Builder is one of the tools in WebdevToolbox’s API Tools category. Create and sign JWT tokens — set header, payload, and secret to generate a valid token. It runs entirely in your browser — no server uploads, no accounts, no waiting.
How to Use It
- Open the tool at /tools/jwt-builder.
- Paste or type your input in the provided field.
- The result updates in real time — no button press needed.
- Use the Copy button to copy the output to your clipboard.
Key Features
- 100% client-side — all processing happens in your browser. Nothing is sent to a server.
- Real-time output — results update as you type, with no submit button required.
- One-click copy — copy the output to your clipboard with a single button press.
- PWA-ready — works offline when installed as a Progressive Web App.
- No proxy required — requests are made directly from your browser, giving you unfiltered responses.
When to Use the JWT Builder
- API testing — make a quick HTTP request without opening Postman or writing a fetch call.
- Documentation generation — build a cURL command to include in your API documentation.
- JWT debugging — create and decode JWT tokens to test your authentication flow.
Try It Now
Open JWT Builder directly from anywhere on the site using ⌘K and typing the tool name. No login required — everything runs offline-capable in your browser.
Part of the API Tools collection on WebdevToolbox — free, browser-based developer tools with no login required.