Developer Utilities

Visual color picker with HEX ↔ RGB ↔ HSL ↔ HSV ↔ CMYK ↔ HWB conversion and WCAG contrast checker — Free online color picker converter

Browse 40+ ready-made CSS box-shadow presets with live preview — Elevation, Soft UI, Colored, Glow, Inset, Layered, Sharp, and Minimal categories. Copy any value instantly - Free online box shadow collection

Browse all 148 named HTML/CSS colors with HEX and RGB values — search, filter by group, and copy any value instantly. Free online HTML color names reference.

Complete reference guide for GET, POST, PUT, PATCH, DELETE, HEAD, and OPTIONS — with semantics, use cases, status codes, and request examples. Free online HTTP method reference.

Build GraphQL queries visually by selecting fields and arguments — supports nested fields, aliases, variables, and mutations. Free online GraphQL query builder.

Preview 80+ Google Fonts with custom text — filter by category, adjust size and weight, and copy the CSS declaration instantly. Free online font preview tool.

Preview all available weights (100–900) of any Google Font side by side with custom text — compare Thin, Light, Regular, Bold, and Black instantly. Free online font weight previewer.

Build responsive CSS media query breakpoints visually with min/max width, height, orientation, and custom conditions — Free online media query builder

Generate a CSS filter string that approximates any hex color from a black source element — Free online hex color to CSS filter converter

Compare two code files or text blocks with side-by-side split view and unified diff highlighting — Free online diff viewer

Look up any Unicode character by name, codepoint, hex value, or paste a character — get HTML entities, CSS escapes, and JS escape sequences instantly

Search Android manifest permission strings with risk levels, protection types, and categories — Free online Android permission reference

Open a WebSocket connection to any ws:// or wss:// URL and send/receive messages in real time — Free online WebSocket tester

Parse and inspect JWK objects or JWKS endpoint responses with field-level validation and human-readable output. Free online JWK inspector.

Measure response time for any public API endpoint with repeated sampling, timeout controls, and CSV export. Free online API latency tester.

Lint env variable names for convention mismatches, reserved key conflicts, duplicates, and invalid formats — Free online env naming linter

Convert cron schedule expressions to equivalent systemd .timer unit configurations with OnCalendar output and starter unit templates - Free online cron to systemd converter

Convert IPv4 addresses to binary notation and back with subnet mask visualization, network address, broadcast address, and host range — Free online IP to binary converter

Build CSS grid layouts visually with column/row track controls, gap settings, alignment, and named template areas — Free online CSS grid generator

Generate .env file templates from variable names with placeholder values, comments, and section grouping — Free online dotenv file generator

Interactive searchable reference for 40+ Git commands with descriptions, flags, and examples — Free online Git cheat sheet

Test JavaScript regular expressions against sample text with real-time match highlighting, capture group display, and all JS regex flags — Free online JS regex tester

Test Python re module regex patterns with live match highlighting, group captures, span positions, and generated Python code — Free online Python regex tester

Interactive reference for all 128 ASCII characters with decimal, hex, octal, and binary values — searchable, filterable, and click-to-copy - Free online ASCII table

Convert OpenAPI 3.x and Swagger 2.0 JSON or YAML specs into readable Markdown API documentation — Free online OpenAPI to Markdown converter

Calculate chmod numeric and symbolic permissions from a visual rwx matrix with setuid, setgid, and sticky bit support — Free online Linux chmod calculator

Generate @import URLs and <link> tags for any combination of Google Fonts and weights — choose font-display strategy, preview fonts live, and copy the CSS instantly - Free online Google Fonts generator