The Brief
Courier is a self-initiated project — a browser-based API testing client built to scratch a real itch. The goal was a tool that felt fast and focused: no account required, no sprawling feature surface, no Electron app to install. Just open it and test a request.
Tools like Postman have become increasingly bloated. Courier was a deliberate constraint exercise: build something that does the core job well, looks considered, and loads instantly.
Design Decisions
The two-panel split layout — white on the left for inputs, deep navy on the right for the response — creates an immediate visual hierarchy between what you send and what you get back. The red brand accent (#ed1c24) gives the app a bold, product-like identity rather than the utilitarian grey that defines most developer tools.
The typography is kept functional: clear labels, monospace where it matters (request body, response output), minimal chrome. The UI gets out of the way of the work.
On mobile, a bottom sheet viewer replaces the split layout — the response slides up after submission rather than competing for screen space in a cramped two-column arrangement.
What Was Built
- Full HTTP method support: GET, POST, PUT, DELETE, PATCH
- Custom header input with add/remove controls
- JSON body editor (contextually hidden for GET requests)
- Authentication tab for token-based requests
- Request timing and status code display
- Persistent request history with one-click clear
- Response clipboard copy
- Responsive layout with mobile bottom sheet viewer
- Branded identity: paper plane logomark, "Fast. Focused. Functional." positioning
Stack
Built with React 19, TypeScript, Tailwind CSS, and Vite. Deployed to Vercel. MIT licensed and open source at github.com/dominic-wood/courier.
