UD5 Toolkit
DNS Lookup - Online Domain Records Checker (A, MX, CNAME)
Query DNS records for any domain directly from your browser using DNS-over-HTTPS. See A, AAAA, MX, CNAME, and TXT records. No logs.
Developer Tools - Utilities for Coders
999+ toolsQuery Parameter Extractor - Online URL Param Table Viewer
Enter a full URL and get all query parameters in a clean table with decoded values. Quickly see UTM and tracking params.
npm Version Range Checker - Online SemVer & Tilde Caret
Enter a package name and version range to see all satisfying versions from the registry. Understand ^ and ~.
Image to Binary Array - Online Pixel Dump
Convert any image into a raw binary array of RGBA values. For use in embedded systems or game development. Copy as Uint8Array.
CSS Compatibility Linter - Online Check Browser Support
Paste your CSS and see warnings for properties that have limited browser support. Links to CanIUse. Modernize safely.
API Status Checker - Online Test Endpoint & Response
Enter an API URL and quickly check its HTTP status code and response time. See response headers and body. Browser fetch.
Shadcn/UI Theme Builder - Online Custom CSS Variables
Pick colors for the shadcn/ui design system and generate the complete CSS variable theme file. Copy into your project.
Browser Storage Quota Estimator - Online Check Limit
Estimate how many MB/GB your storage can hold based on navigator.storage.estimate() and display as a pie chart.
ASCII Table - Online Character Code Reference
Interactive ASCII table showing decimal, hex, octal, and binary codes for all standard and extended ASCII characters. A classic programmer reference.
CSS Progress Bar Generator - Online Animated & Styled
Create a custom HTML/CSS progress bar with percentage, colors, and animation. Copy the code. Modern UI element.
PWA Install Prompt Checker - Online See beforeinstallprompt Status
Check if the browser has captured the beforeinstallprompt event. Understand why your PWA is (or isn't) installable.
Clipboard API Tester - Online Read & Write Sandbox
Experiment with the Async Clipboard API: read/write text and images from the clipboard. Verify permissions and see demo code.
Font Fallback Checker - Online See Missing Glyphs
Type any character and see how it renders in different font stacks. Detect missing glyphs and fallback behavior.
CSS Glow Hover Effect - Online Animated Box Shadow
Design a button or card that glows on hover. Adjust shadow color, spread, and transition. Copy the CSS. Rich UI.
Unix Timestamp Converter - Online Epoch & DateTime Tool
Convert Unix timestamps to human-readable dates and vice versa. Supports seconds and milliseconds. Ideal for developers debugging time-related code.
Vibration API Demo - Online Test Haptic Feedback
Trigger different vibration patterns on mobile devices. Test if your phone supports haptic feedback. Simple demo.
CSS Checkerboard Pattern - Online Background Generator
Create a customizable checkerboard or grid background using pure CSS gradients. Adjust cell size and colors. Copy the code.
CSS Letterpress Text Effect - Online Inset Typography
Create a realistic letterpress (debossed) text effect using CSS text‑shadow and background. Adjust depth and light direction. Copy code.
Fuzzy Data Generator - Online Create Random Records
Generate random but realistic‑looking data arrays (users, products, orders) with typos and missing fields. For test robustness.
Gray Code Converter - Online Binary to Reflected Code
Translate between binary and Gray code (reflected binary code). See the bit changes. Useful for digital logic.
Text Decoration CSS Generator - Online Underline & Strike
Style underlines, overlines, and strike-throughs with colors, wavy styles, and thickness. Modern CSS text‑decoration.
Gamepad API Tester - Online Visual Controller Check
Connect a gamepad and see all button presses and axis movements visually. Check that every input is detected correctly.
URL Parser - Online Decompose Link into Components
Break down any URL into its individual components: protocol, hostname, path, query parameters. Decode query strings easily. Purely client-side.
Network Throttle Simulator - Online Slow 3G & Offline Test
Test how your page loads under slow, 3G, or offline conditions by intercepting fetch and applying delays. No DevTools needed.
Fullscreen API Tester - Online Request & Exit Demo
Test the Fullscreen API: request fullscreen on a colored div, detect changes, and copy the JavaScript boilerplate.
CSS Subgrid Layout Builder - Online Align Nested Grids
Design a layout where nested grids share track sizes with their parent via subgrid. Copy the complete CSS.
Image to CSS Grid Layout - Online Pixel‑Based Generator
Upload a small pixel art image and get a CSS grid layout that recreates it using divs. Novelty developer tool.
Cookie String Parser - Online Decode & Format Browser Cookies
Paste a raw cookie string and see a formatted key‑value table. Debug session cookies and understand flags. Runs in browser.
Noise Texture & Grain Generator - Online CSS Background
Generate a subtle noise/grain texture as a CSS background pattern. Adjust opacity and size. For that film look.
Image Format MIME Checker - Online Identify True Type
Drop an image that might have wrong extension and see its real format (JPEG, PNG, WebP) based on header bytes.
Signed Magnitude Converter - Online Negative Binary Numbers
Encode decimal integers into signed magnitude binary representation and decode back. Learn computer arithmetic.
GraphQL Playground - Online Query & Schema Explorer
Execute GraphQL queries against any endpoint with variables and headers. Explore schema via introspection. All requests made directly from your browser.
PNG Chunk Extractor - Online View Hidden Metadata
Drop a PNG file and see all its chunks (IHDR, tEXt, etc.). Extract hidden text and color profiles. Pure JavaScript reader.
Pointer Events Playground - Online Mouse, Touch & Pen
Unified input demo: see pressure, tilt, and type from any pointer. Compare pointerType values. Essential for drawing apps.
ImageDecoder API Demo - Online Progressive Decode
Decode an image progressively using the ImageDecoder API. See partial results and metadata. Modern alternative to <img>.
Lottie Animation Previewer - Online JSON Player
Paste Lottie JSON code or upload a .json file and see the animation play. Control speed and loop. Perfect for developers.
JSON to Graph Visualization - Online Tree Diagram
Paste a JSON object and see a dynamic, draggable tree graph representation. Excellent for debugging nested data.
Neon Sign Text Effect - Online Glowing CSS Generator
Design a realistic neon sign text with multiple layers of glow. Copy the CSS and HTML. Perfect for headers.
Website Color Theme Extractor - Online Grab Palette from CSS
Fetch a website's CSS and extract :root custom properties (‑‑color) to reveal its design token palette. For learning and inspiration.
Iframe Sandbox Configurator - Online Test Permissions
Build an iframe with different sandbox flags and see live which features are blocked. For secure embedding.
Favicon Checker - Online Test Any Site's Icon
Enter a URL and see its favicon at all standard sizes. Check if it's properly defined. SEO basic check.
File MIME Type & Magic Bytes Detector - Online
Drop a file to see its MIME type and the first few magic bytes (hex and ASCII). No upload, works instantly.
Font Awesome Cheatsheet - Online Icon Search & Copy
Browse and search all Font Awesome 6 icons with preview, class name, and unicode. Copy the HTML snippet. Perfect for web developers.
WebCodecs Video Frame Reader - Online Decode & Display
Decode individual video frames from a local file using the VideoDecoder API. Step through frames. Cutting‑edge browser feature.
Web Image Size Calculator - Online KB & Dimensions Tool
Predict the file size of an image based on pixel dimensions and format (JPEG, PNG, WebP). Rough estimate. Local.
Emoji Favicon Maker - Online Convert Emoji to .ico
Pick an emoji and convert it into a proper favicon .ico file for your website. No design skills needed. Instant download.
Online Screen Ruler - Measure Pixels & Inches on Screen
An on‑screen ruler that measures in pixels, centimeters, and inches. Drag to resize. Handy for UI designers and developers.
HTML to Markdown Converter - Online Clean Content Extractor
Strip HTML tags and convert web content to plain Markdown. Preserve headings, lists, and links. Perfect for content migration. All processing in browser.
Hex to Float Converter - Online IEEE 754 Decoder
Enter a hexadecimal string and decode it as a 32‑bit or 64‑bit floating‑point number. Low‑level developer tool.
Fake ID Number Generator - Online Test SSN/SIN Lookalike
Generate random, formatted ID numbers that match pattern rules for various countries. For testing input validation. No real data.
Speech Recognition Tester - Online Web Speech API Demo
Test your browser's built‑in speech recognition. Speak and see the transcribed text appear live. Must‑have for voice app devs.
PRNG Validator - Online Check Randomness Pattern
Paste a list of numbers to visually check uniformity, mean, and simple pattern analysis. Educational tool for statistics and RNG.
JSON Path Finder - Online Search & Extract from Object
Search and extract values from a large JSON object using dot/bracket notation. Quickly locate deeply nested fields. Data stays local in your browser.
CSS Beautifier & Formatter - Online CSS Organizer
Beautify and format your CSS stylesheets instantly. Organize, minify, or prettify CSS code for better readability. Processed securely on client-side.
Browser Font Stacks Explorer - Online Defaults Per OS
See which fonts map to generic families (serif, sans‑serif, monospace) on different operating systems. A handy reference.
Screen Orientation API Tester - Online Lock & Check
Check current screen orientation and test the lock API. Useful for mobile web apps. Demo with code.
Advanced CSS Gradient Builder - Online Multi‑Stop & Angle
Create complex linear gradients with any number of color stops, exact angles, and length units. Live preview and CSS code.
Random User Activity Simulator - Online Test Idle Logic
Simulate random mouse moves, clicks, or keystrokes to test idle‑timeout logic. Stops when you move the mouse. Dev test.
CSS Grid Playground - Online Interactive Layout Builder
Experiment with CSS Grid properties visually. Add rows, columns, and areas. See the grid in action and copy the code.
Decimal to IEEE 754 Converter - Online Float Representation
Convert a decimal number to 32-bit single precision IEEE 754 format. See sign, exponent, mantissa bits. Developer tool.