Free Online Converters
Convert data and generate CSS utilities without installing one-off CLIs. This hub covers JSON transforms, color tools, timestamps, markdown/HTML, and layout generators. Everything is local-first on DevTooKit so sample payloads and brand tokens stay on your device.
36 tools in this category · 91 total on DevTooKit · local-first, no upload
Tools in Converters
- Config Format ConverterConvert between JSON, YAML, TOML, and XML configuration formats.
- JSON ↔ CSVConvert JSON arrays to CSV and back, with header detection.
- Color ConverterConvert between HEX, RGB, HSL with live swatch preview.
- Unix Timestamp ConverterConvert Unix timestamps to human-readable dates and back.
- Case ConverterConvert text between camelCase, snake_case, kebab-case, PascalCase, etc.
- Number Base ConverterConvert numbers between binary, octal, decimal, and hex.
- CSS Gradient BuilderVisually build linear, radial, and conic gradients with multiple color stops.
- JSON → TypeScriptGenerate TypeScript interfaces from JSON objects. Nested objects become separate types.
- JSON SorterSort JSON keys alphabetically, flatten nested objects, or unflatten dotted keys.
- File Size ConverterConvert between bytes, KB, MB, GB, TB, KiB, MiB, GiB. Includes download time estimates.
- CSS Unit ConverterConvert between px, rem, em, pt, in, cm, mm, vw, vh, and %. Configurable root font size.
- Slug GeneratorConvert titles to URL-safe slugs. Configurable separator, case, stop words, max length.
- Image ↔ Base64Convert images to Base64 data URLs and back. Drag-and-drop, preview, download.
- Time Zone ConverterConvert a date/time across 18 common time zones with live current-time ticker and DST detection.
- Unicode LookupSearch Unicode characters by char, codepoint, or name. Browse by block. Copy as HTML/JS/CSS.
- JSON DiffDeep-compare two JSON objects and see added, removed, and changed paths side-by-side.
- JSON → GoGenerate Go structs from JSON with JSON tags. snake_case keys become PascalCase.
- JSON → ZodGenerate Zod schemas from JSON. Auto-detects dates, UUIDs, emails, URLs. With z.coerce option.
- Color Contrast CheckerCheck WCAG 2.1 contrast ratio between two colors. Get AA/AAA pass/fail for normal and large text.
- Box Shadow GeneratorVisually build CSS box-shadows with multiple layers, inset, spread, and color (with alpha). 6 presets.
- Markdown Table GeneratorConvert CSV / TSV / spreadsheet data to a Markdown table with per-column alignment control.
- Code ScreenshotGenerate beautiful code screenshots (carbon-style) with syntax highlighting, themes, and window controls.
- Regex VisualizerVisualize a regex as a Thompson NFA state machine graph. See states, transitions, and epsilon moves.
- CSS Animation GeneratorVisually build CSS @keyframes animations with 8 presets, timing functions, and live preview.
- SVG Icon BrowserBrowse 184 curated SVG icons (Lucide-style). Adjust size, stroke, color, fill. Copy as SVG or React.
- CSS Flexbox GeneratorVisually build flexbox layouts. Adjust direction, justify, align, wrap, gap. Live preview + CSS.
- CSS Grid GeneratorVisually build CSS Grid layouts. Adjust columns, rows, gap, alignment. Live preview + CSS.
- Border Radius GeneratorVisually build CSS border-radius. Per-corner control, 8 presets (Pill, Blob, Leaf, Ticket, Wave).
- CSS Filter GeneratorVisually build CSS filters: blur, brightness, contrast, grayscale, hue-rotate, sepia, more.
- JSON → PythonGenerate Python @dataclass classes from JSON. Type hints, snake_case keys, nested classes.
- CSS Transform GeneratorVisually build CSS transforms: rotate, scale, skew, translate. Live preview with sliders.
- Placeholder Image GeneratorGenerate placeholder images with custom dimensions, colors, and text. Download as PNG.
- Markdown → HTMLConvert Markdown to clean HTML with live preview. Supports headings, tables, code blocks, links.
- HTML → Markdown / JSXConvert HTML to Markdown or React JSX. Maps class→className, styles, and void tags correctly.
- User Agent ParserParse User-Agent strings to detect browser, OS, device type, and rendering engine.
- CIDR / IP Subnet CalculatorCalculate network, broadcast, netmask, usable hosts, and binary masks from an IPv4 CIDR.
FAQ — Converters
Are converters free?
Yes — free to use with no account wall for core conversion workflows.
Why are CSS generators listed under converters?
They transform visual settings into copy-ready CSS, alongside data converters like JSON ↔ CSV.