Development
Ship code faster with browser utilities for formatting, diffs, timestamps, and docs
Everyday helpers for regex testing, diffs, cron expressions, Docker snippets, Markdown cleanup, and other build-and-debug chores.
This category collects the tools you reach for during implementation, review, and incident response when installing another CLI would be slower than solving the task in the browser.
Tools in this hub
Featured picks
Language support
Common tasks
Test patterns, output, and formatting
Validate regexes, compare revisions, and clean up source snippets before they land in a commit or issue.
Translate operations into safer config
Convert timestamps, cron ideas, and Docker commands into readable values teammates can reuse.
Prepare technical documentation quickly
Format Markdown, generate examples, and produce development support content without leaving the browser.
Featured tools
Start with the registered tools that cover the most common jobs in this workflow, then browse the full list.
Regex Tester & Debugger
Free online regex tester to match, replace, and debug regular expressions with real-time highlighting and capture group support.
curl to Code Converter — Python, JavaScript, Go & More
Paste a curl command and get equivalent Python requests, fetch, axios, Go, PHP, Ruby, C# or PowerShell code. Runs in your browser.
HTML to JSX Converter — Paste Markup, Get React
Convert HTML into valid JSX: class becomes className, inline styles become objects, void elements self-close, and comments are converted.
SemVer Range Tester — Check ^ and ~ Version Ranges
Expand npm version ranges into concrete comparators and see exactly which versions satisfy them, including prerelease handling.
IEEE 754 Float Inspector — Bits, Exponent & Rounding
See the sign, exponent and mantissa bits of any float32 or float64 value, the exact stored result, the rounding error and the adjacent representable values.
Text, JSON & YAML Diff Viewer
Compare text, JSON, or YAML side by side or as a unified diff. Structured modes parse, recursively sort keys, and expose meaningful changes.
Unix Timestamp Converter
Free online Unix timestamp converter to convert between epoch timestamps and human-readable dates in ISO, UTC, and local formats.
Crontab Generator, Explainer & Next Run Calculator
Build and explain five-field Unix cron expressions, calculate timezone-aware future runs, inspect DST behavior, and follow a live countdown.
All tools in this category
Browse every registered tool in this category and keep moving through the real task at hand.
Kubernetes YAML Validator & Manifest Linter
Parse multi-document Kubernetes YAML and find missing fields, container conflicts, invalid resources, and operational hardening opportunities.
OpenAPI Diff & Breaking Change Checker
Compare two OpenAPI 3 JSON or YAML documents and identify endpoint, parameter, response, and schema changes with breaking-change classification.
Regex Tester & Debugger
Free online regex tester to match, replace, and debug regular expressions with real-time highlighting and capture group support.
curl to Code Converter — Python, JavaScript, Go & More
Paste a curl command and get equivalent Python requests, fetch, axios, Go, PHP, Ruby, C# or PowerShell code. Runs in your browser.
Unix Timestamp Converter
Free online Unix timestamp converter to convert between epoch timestamps and human-readable dates in ISO, UTC, and local formats.
HTML to JSX Converter — Paste Markup, Get React
Convert HTML into valid JSX: class becomes className, inline styles become objects, void elements self-close, and comments are converted.
SemVer Range Tester — Check ^ and ~ Version Ranges
Expand npm version ranges into concrete comparators and see exactly which versions satisfy them, including prerelease handling.
SVG to JSX — Convert SVG into a React Component
Turn SVG markup into a ready-to-paste React component with camelCase props, currentColor theming, TypeScript typings, and a safe preview.
Code Minifier — Shrink CSS, JavaScript and HTML
Remove comments and redundant whitespace from CSS, JavaScript or HTML in your browser, and see exactly how many bytes each change saves.
Color Converter & Picker
Free online color converter and picker tool to convert between HEX, RGB, and HSL formats with a visual color preview.
Crontab Generator, Explainer & Next Run Calculator
Build and explain five-field Unix cron expressions, calculate timezone-aware future runs, inspect DST behavior, and follow a live countdown.
Text, JSON & YAML Diff Viewer
Compare text, JSON, or YAML side by side or as a unified diff. Structured modes parse, recursively sort keys, and expose meaningful changes.
IEEE 754 Float Inspector — Bits, Exponent & Rounding
See the sign, exponent and mantissa bits of any float32 or float64 value, the exact stored result, the rounding error and the adjacent representable values.
Structured Log & NDJSON Explorer
Parse mixed NDJSON, JSON Lines, logfmt, and Apache or nginx access logs locally, then filter, summarize, and export matching events.
Font Inspector & Subsetter — Inspect TTF/OTF Glyphs
Inspect TTF and OTF font metadata, supported characters, metrics, and glyph counts, then build a smaller subset font from the exact text you need.
Text Case & Format Converter
Free online text case converter to transform text between camelCase, snake_case, PascalCase, kebab-case, and 10+ other formats instantly.
Chmod Permission Calculator
Free online chmod calculator to set Unix/Linux file permissions. Convert between octal, symbolic notation, and get the chmod command instantly.
Docker Run to Compose Converter
Free online tool to convert docker run commands to docker-compose.yml format. Instantly transform container commands into composable YAML configurations.
Code Formatter — Prettier Online
Free online code formatter powered by Prettier. Format JavaScript, TypeScript, HTML, Vue, CSS, SCSS, JSON, YAML, Markdown, and GraphQL with customizable options. No sign-up required.
Fake Data Generator
Generate 1–100 realistic fake values for testing and development, with exact whole-number count validation, multiple data types, locales, and output formats.
URL Slug Generator
Free online URL slug generator. Convert any text to SEO-friendly, URL-safe slugs with customizable separators, case options, and length limits.
Mermaid Live Editor — Diagram Generator
Free online Mermaid diagram editor. Create flowcharts, sequence diagrams, class diagrams, Gantt charts, pie charts, and mind maps. Export to SVG or PNG. No sign-up required.
CSS Unit Converter
Free online CSS unit converter. Convert between px, rem, em, pt, %, vw, and vh with customizable base font size and viewport dimensions.
Lorem Ipsum Generator
Free online Lorem Ipsum placeholder text generator. Generate dummy text by paragraphs, sentences, or words for mockups and designs.
Accessibility Color Contrast Checker
Free online WCAG color contrast checker. Calculate contrast ratios, verify AA/AAA compliance, preview text readability, and simulate color blindness for accessible design.
Date-Time Converter with Timezone Support
Free online date-time converter to convert dates and times across timezones. Supports ISO 8601, RFC 2822, Unix timestamps, and relative time — powered by native Intl APIs.
Git Cheatsheet - Quick Command Reference & Memo
Free online Git cheatsheet with searchable commands organized by category. Quickly find Git commands for branching, merging, rebasing, stashing, resetting, and more.
Git Commit Message Generator
Free online Git commit message generator using the Conventional Commits format. Build structured commit messages with type, scope, description, body, breaking changes, and footer fields.
Nginx Config Generator
Free online Nginx configuration file generator. Build server blocks with SSL, reverse proxy, gzip, security headers, WebSocket support, and more — no manual editing required.
Keycode Info
Capture a browser keydown event and inspect key, code, keyCode, location, and modifier flags for keyboard shortcut debugging.
MIME Type Lookup
Look up common file extension to MIME type mappings, or reverse a MIME type into the built-in list of matching extensions.
PDF Signature Checker
Inspect an uploaded PDF for signature dictionaries, ByteRange entries, SubFilter values, and embedded signature contents.
FILETIME & LDAP Timestamp Converter
Free online FILETIME and LDAP/Active Directory timestamp converter. Convert 18-digit Windows FILETIME to human-readable dates and back. Live clock included.
Dockerfile Linter
Analyze your Dockerfile for best practices, security issues, and optimization opportunities with instant feedback and actionable suggestions.
Tailwind CSS Class Sorter — Organize Utility Classes
Free online Tailwind CSS class sorter. Organize utility classes following the official recommended order with duplicate removal. No sign-up required.
Color Space Explorer — OKLCH, OKLab, P3 & More
Free online extended color space converter. Convert between HEX, RGB, HSL, HWB, OKLab, OKLCH, Linear sRGB, and Display P3 with CSS output. No sign-up required.
GraphQL Playground — Schema Validator & Query Formatter
Free online GraphQL playground. Validate queries against your schema, format GraphQL queries, and inspect schema types. Works offline, no sign-up required.
Benchmark Builder — JavaScript Performance Testing
Compare synchronous JavaScript snippets in disposable local workers with time limits, operations-per-second metrics, and visual results.
Figma Token Converter — Design Tokens to CSS/Tailwind
Free online Figma design token converter. Transform JSON design tokens to CSS custom properties, SCSS variables, Tailwind config, or JS exports. No sign-up required.
Related categories and collections
Continue with adjacent category pages and task collections that solve the next step.
Data formats
Structured data tools for JSON formatting, YAML and XML conversion, schema validation, CSV editing, and API-ready output.
Web & auth
Practical browser utilities for JWTs, HTTP requests, headers, cookies, SEO checks, OpenAPI files, and other web troubleshooting tasks.
Text
Browser-based text helpers for Markdown, lists, tables, Unicode lookups, readability checks, and reusable snippets.
PDF & documents
A focused collection for PDF signature checks, document markup prep, tables, and file-to-text workflows. Fuller document editing remains a roadmap item.
Education & study
A mixed collection for homework, revision, classroom examples, notes, and self-checks across math, statistics, Markdown, and text-focused practice.