Free online developer tools — JSON, JWT, Base64, Regex, Timestamps, Diff, UUID, Hash, Color, Base
A minimalist developer tools workspace — a web-based suite of utilities for common developer tasks, with a dark-themed UI and responsive split-panel layout.
| Tool | Description |
|---|---|
| JSON | Format (pretty-print) or minify JSON with live validation |
| JWT | Decode JWT tokens — header, payload, signature, expiry info |
| Encode | Base64 and URL encode/decode |
| Regex | Test regex patterns with live match highlighting and flags (g, i, m) |
| Time | Convert Unix timestamps and ISO 8601 strings, with local/UTC toggle |
| Diff | Side-by-side text diff using LCS algorithm, with unified copy |
| UUID | Generate v4 UUIDs in bulk, with uppercase/no-dashes formatting |
| Hash | SHA-1, SHA-256, SHA-384 and SHA-512 digests via the Web Crypto API |
| Color | Convert between HEX, RGB and HSL, with a native color picker and preview |
| Base | Convert numbers between binary, octal, decimal and hexadecimal |
- Next.js 16 (App Router, React Server Components)
- React 19
- TypeScript 5 (strict mode)
- Tailwind CSS v4
- shadcn/ui + Radix UI
- Lucide React icons
pnpm install
pnpm devOpen http://localhost:3000.
src/
├── app/ # Next.js App Router (layout, page, global styles)
├── components/ # Shared UI (Sidebar, Toolbar, SplitPanel, Workspace)
│ └── ui/ # shadcn/ui primitives (Button, ...)
├── tools/ # One directory per tool (json, jwt, encode, regex, time, diff, uuid, hash, color, numberbase)
└── lib/ # Utilities (cn helper)