Free online developer toolbox with intelligent content detection. Paste JSON, HTML, JWT, curl, or any text and get the right tool instantly. No sign-up required.
- ⭐ No sign-up – Use every tool without an account or paywall.
- ⭐ Runs in your browser – Your data stays on your device; we don’t store or log your input.
- ⭐ Paste and go – Paste JSON, HTML, JWT, curl, Base64, or any text on the homepage and Spoold suggests the right tool.
- ⭐ One place for many tools – Format JSON, decode JWTs, convert timestamps, generate UUIDs, test regex, convert curl to code, and more.
- ⭐ Fast and private – Instant results; no server round-trip for most tools.
| Tool | Description |
|---|---|
| JSON Formatter | Format, validate, and beautify JSON online instantly. Interactive tree view, syn… |
| JSON Diff | Compare two JSON objects side by side with visual diff highlighting. See additio… |
| JSON ↔ YAML | Convert JSON to YAML and YAML to JSON instantly with bidirectional conversion. A… |
| HTML Preview | Live HTML preview with full CSS and JavaScript support. Test responsive designs,… |
| JWT Decoder | Decode and inspect JWT tokens instantly. View header, payload, claims, and expir… |
| Unix Time Converter | Convert Unix timestamps to human-readable dates and vice versa. Multiple timezon… |
| CSV Viewer & Converter | Preview CSV files with intelligent auto-delimiter detection. Convert to JSON, so… |
| URL Parser | Parse and inspect URLs with detailed breakdown. View and edit query parameters, … |
| QR Code Generator & Scanner | Generate QR codes from text or URLs with custom colors and sizes. Scan QR codes … |
| Regex Tester | Test regular expressions with live matching and highlighting. Support for all re… |
| Markdown Preview | Live Markdown preview with full GitHub Flavored Markdown support. Syntax highlig… |
| curl to Code Converter | Convert curl commands to code snippets in JavaScript, Python, Node.js, and more.… |
| Mermaid Diagram Renderer | Create and preview Mermaid diagrams online. Supports flowcharts, sequence diagra… |
| Base64 Encoder/Decoder | Encode text to Base64 or decode Base64 to text instantly. Supports URL-safe enco… |
| JSON Escape/Unescape | Escape JSON strings for embedding in other JSON or unescape escaped JSON strings… |
| PDF Viewer | Convert Base64 or hex encoded PDF bytes to viewable PDF instantly. Preview, down… |
| Gzip Compress/Decompress | Compress text with gzip or decompress gzip data online. Supports base64 and hex … |
| Universal Encoder/Decoder | Unified encoder/decoder with auto-detection. Supports Base64, Hex, Unicode, Bina… |
| Hex Encoder/Decoder | Encode text to hexadecimal or decode hex strings to text. Bidirectional conversi… |
| Unicode Encoder/Decoder | Encode text to Unicode escape sequences or decode Unicode escapes to text. Suppo… |
| Binary Encoder/Decoder | Encode text to binary or decode binary strings to text. Supports ASCII and UTF-8… |
| HTML Entities Encoder/Decoder | Encode special characters to HTML entities or decode HTML entities to text. Supp… |
| Online Code Editor | Universal code editor with syntax highlighting for 40+ languages. Edit TypeScrip… |
| Online Text Editor | Simple and fast plain text editor for writing notes, code snippets, or any text … |
| Flow Canvas | Create visual flow diagrams by clicking anywhere on canvas. Auto-detects keyword… |
| UUID Generator & Validator | Generate UUIDs (v4 random, v1 timestamp, v7 time-ordered, nil) and validate UUID… |
| Hash Generator & HMAC | Hash text or files with MD5, SHA-1, SHA-256, SHA-384, SHA-512. HMAC signing, ver… |
Spoold is built for developers who need quick, reliable tools without leaving the browser. Paste something on the homepage and we detect the format (JSON, HTML, JWT, curl, Base64, UUID, etc.) and open the right tool. All processing runs client-side where possible, so your data never has to touch our servers.