Programming
Editors, playgrounds and generators for everyday coding.
- Diff CheckerCompare two blocks of text line by line and see exactly what was added, removed or left unchanged.Open tool
- Unix Timestamp ConverterConvert a Unix timestamp to a readable date and back. Detects seconds, milliseconds, microseconds and nanoseconds, and always answers in UTC.Open tool
- Case ConverterConvert names between camelCase, snake_case, kebab-case, PascalCase and CONSTANT_CASE. Handles acronyms, and converts a whole column at once.Open tool
- Cron Expression ParserRead a cron expression in plain English and see exactly when it next runs. Catches the day-of-month and day-of-week trap that fires jobs twice.Open tool
- Color ConverterConvert between HEX, RGB, HSL and HSV, and check WCAG contrast. Uses the published luminance formula, not a brightness average.Open tool
- Number Base ConverterConvert between binary, octal, decimal, hexadecimal and any base up to 36. Exact at any size, including full 64-bit values.Open tool
- Word CounterCount words, characters, sentences and paragraphs, with reading time and the three different character counts that matter in code.Open tool
- CIDR Subnet CalculatorWork out the network, broadcast, mask, wildcard and usable host range for any IPv4 CIDR block. Handles /31 and /32 correctly.Open tool
- Slug GeneratorTurn a title into a clean URL slug. Accented and non-Latin letters survive instead of being deleted, and separators never double up.Open tool
- Lorem Ipsum GeneratorGenerate placeholder paragraphs, sentences or words. A fixed seed produces the same text every time, so mockups stay comparable.Open tool
- Regex TesterTest a regular expression against sample text with live highlighting, capture groups and replacement. A runaway pattern cannot freeze the page.Open tool
- Duration ConverterConvert a duration between milliseconds, seconds, minutes, hours and days. Reads 1h30m, PT1H30M and 01:30:00, and converts to all of them.Open tool
- Line ToolsSort lines alphabetically or naturally, remove duplicates and blanks, trim, reverse and number them. Natural order puts item2 before item10.Open tool
- Semver Range CheckerCheck whether a version satisfies an npm range, and see the range desugared. Explains the prerelease rule that excludes 1.2.4-beta from ^1.2.3.Open tool
- Cron Dialect ConverterConvert a cron expression between Unix, Quartz, AWS EventBridge and Spring. Handles the day-of-week numbering difference that silently reschedules jobs.Open tool
- Discord Timestamp GeneratorMake Discord <t:…> timestamp tags in all nine styles, preview each in any time zone and language, and decode tags you already have. Catches milliseconds.Open tool
- Chmod CalculatorConvert chmod permissions between octal (755), ls -l (rwxr-xr-x) and symbolic (u+x), with setuid, setgid and sticky bits explained in plain English.Open tool
- HTML to JSX ConverterConvert HTML to JSX: class to className, style strings to objects, void tags closed, SVG attributes camelCased, and whitespace kept as React renders it.Open tool
- docker run to ComposeConvert docker run commands to a compose.yaml. Ports, volumes, networks, GPUs and environment mapped to the Compose Specification, with $ escaped.Open tool
- JSON to TypeScriptGenerate TypeScript interfaces, type aliases or a Zod schema from JSON. Array elements are merged, so a key missing from some of them becomes optional.Open tool
- Markdown PreviewPreview Markdown as you type and copy the HTML. CommonMark 0.31.2 with GitHub tables, task lists and strikethrough; raw HTML stays off unless you allow it.Open tool
- JSON to GoGenerate Go structs from JSON with json tags, int64 or float64 per field, pointers for null or missing keys, and time.Time for RFC 3339 dates.Open tool
- JSON to C#Generate C# classes or records from JSON for System.Text.Json or Newtonsoft.Json, with nullable types, required properties and the right number types.Open tool
- CSS MinifierMinify CSS without breaking it, or beautify it with one declaration per line. calc() spacing, descendant selectors and /*! licences survive.Open tool
- JSON to JavaGenerate Java POJOs or records from JSON with Jackson or Gson annotations, boxed types for null, long or BigDecimal numbers and java.time dates.Open tool
- JSON to KotlinGenerate Kotlin data classes from JSON for kotlinx.serialization, Moshi or Gson, with nullable types, null defaults for optional keys and Long or Double.Open tool
- JSON to DartGenerate null-safe Dart model classes from JSON, with fromJson and toJson or json_serializable, doubles read through num, lists and DateTime.Open tool
- PX to REM ConverterConvert px to rem, rem to px, em, pt and every CSS length at any root font size, or a whole stylesheet at once. Media queries and 1px borders handled.Open tool
- IP Address ConverterConvert an IPv4 or IPv6 address to decimal, hex, binary and octal, expand or compress IPv6, and see which range it is in. Flags the forms SSRF filters miss.Open tool
- HTML Formatter and MinifierBeautify HTML with clean indentation, or minify it, changing only whitespace a browser ignores. Inline spacing, <pre> and <textarea> stay as they render.Open tool
- HTML to Markdown ConverterConvert HTML to Markdown for GitHub or CommonMark: tables, task lists and code blocks, with text escaped so it renders back exactly as the HTML did.Open tool