A fast, privacy-first online toolbox for developers. Paste JSON, HTML, JWT, curl commands, Base64, or any text — Spoold instantly detects the format and opens the right tool.
No accounts, no ads, no tracking.
- ⭐ No sign-up required — All tools work instantly, no account or paywall.
- ⭐ Runs entirely in your browser — Your data stays private; nothing is stored or logged.
- ⭐ Paste → Auto-detect → Tool opens — JSON, HTML, JWT, curl, Base64, UUID, and more.
- ⭐ Dozens of developer tools in one place — From JSON formatting to QR generation.
- ⭐ Fast, lightweight, and private — Designed for speed; most features run client-side.
| Tool | Description |
|---|---|
| JSON Formatter | Format and validate JSON with tree view & syntax highlighting. |
| JSON Diff | Compare two JSON objects with visual diff highlights. |
| JSON ↔ YAML | Convert between JSON and YAML instantly. |
| HTML Preview | Real-time HTML/CSS/JS preview with responsive testing. |
| JWT Decoder | Decode JWT headers, payloads, claims, and expiry. |
| Unix Time Converter | Convert Unix timestamps ↔ readable date formats. |
| CSV Viewer & Converter | View CSV with auto-delimiter detection; export to JSON & more. |
| URL Parser | Inspect URLs, edit query params, and parse components. |
| QR Generator & Scanner | Create and scan QR codes with customizable options. |
| Regex Tester | Test Regex with live matching and highlighting. |
| Markdown Preview | Live GitHub-Flavored Markdown preview with syntax highlighting. |
| curl → Code Converter | Convert curl commands to JS, Python, Node.js, Go, and more. |
| Mermaid Renderer | Create & preview Mermaid diagrams (flowchart, sequence, etc.). |
| Base64 Encoder/Decoder | Encode/decode Base64 (text, files, URL-safe). |
| JSON Escape/Unescape | Escape or unescape JSON strings for embedding. |
| PDF Viewer | Convert Base64/hex PDF bytes into a readable PDF viewer. |
| Gzip Compress/Decompress | Gzip compress or decompress text (supports Base64 & hex). |
| Universal Encoder/Decoder | Auto-detect and convert Base64, Hex, Unicode, Binary, etc. |
| Hex Encoder/Decoder | Convert text ↔ hex strings bidirectionally. |
| Unicode Encoder/Decoder | Encode/decode Unicode escape sequences. |
| Binary Encoder/Decoder | Convert text ↔ binary (ASCII & UTF-8 support). |
| HTML Entities Encoder/Decoder | Encode/decode HTML entity characters. |
| Online Code Editor | Lightweight code editor supporting 40+ languages. |
| Online Text Editor | Minimal fast editor for notes, snippets, or plain text. |
| Flow Canvas | Create flow diagrams by clicking—auto-detects keywords. |
| UUID Generator & Validator | Generate v1, v4, v7, NIL UUIDs; validate any UUID. |
| Hash Generator & HMAC | MD5, SHA-1, SHA-256, SHA-512 hashing + HMAC signing. |
Spoold is built for developers who want reliable browser-based utilities without switching tabs or installing apps. Just paste something on the homepage — Spoold detects if it’s JSON, HTML, Base64, curl, JWT, UUID, etc., and routes you to the right tool automatically.
Most tools run entirely client-side, ensuring speed and total privacy.