Barcode Scanner Simulator β Online Enter Number & Visualize
Type a UPC or EAN number and see how a laser scanner would identify it, plus check digit validation.
UD5 Toolkit
Type a UPC or EAN number and see how a laser scanner would identify it, plus check digit validation.
Simulate memory page reference strings with FIFO, LRU, and Optimal algorithms. See page fault count. OS concept demo.
Convert any date into Roman numerals (dayβmonthβyear) for tattoos or special occasions. Clean and local.
Enter a URL and fetch its Twitter card meta tags. See a live preview of how the tweet will appear. Debug social sharing.
Open many parallel WebSocket connections and send messages. Test your server's concurrency. All from your browser.
Keep track of a tennis match: points, games, sets, and deuce. Supports tiebreak. Great for friendly matches. Local.
Enter a URL and see a preview of how it will appear when shared on Facebook, Twitter, LinkedIn. Detect missing tags.
Roll any number of dice thousands of times and see a live bar chart of the sum distribution. Great for game designers.
Select functional groups to see an approximate IR absorption spectrum. Learn spectroscopy visually. All local.
Simulate random mouse moves, clicks, or keystrokes to test idleβtimeout logic. Stops when you move the mouse. Dev test.
Type a few words and see them rendered at every heading size (h1βh6) with your chosen font. Perfect for design systems.
Set a cron expression and see a calendar of the next 1,000 execution times. Never miss a schedule again.
Get a random tattoo concept with style and placement suggestion. For fun and inspiration only. Not real art.
Adjust ISO, aperture, and shutter speed sliders and see how it affects the exposure of a sample scene. Learn photography basics.
Preview how a CMYK value will look on screen (approximate). Compare with its RGB equivalent. Preβpress check.
Paste multiple HTML snippets (header, footer) and a main content, then combine them into a single preview. Static site helper.
Select telescope and eyepiece parameters to see the field of view circle on a simulated night sky image.
Watch the planets orbit the Sun in a topβdown 2D view. Adjust speed and zoom. Distances not realistic; beautiful model.
Arrange virtual fabric squares or triangles on a grid to preview a quilt pattern. Change colors and sizes. Export layout.
Fold a virtual square paper step by step with crease lines and visual previews. Practice origami basics without wasting real paper. All canvasβbased.
Paste your Swagger/OpenAPI YAML and see a rendered API documentation preview with expandable endpoints. All local rendering.
Convert any date into Roman numerals (dayβmonthβyear) for tattoos or special occasions. Clean and local.
Drag to see how a solar eclipse occurs. Visualize the moon's shadow. Educational and interactive.
Enter a URL and get a rough client-side performance simulation: request count, DOM size, and potential speed tips. No real Lighthouse.
Enter a URL to see exactly what Open Graph and Twitter card tags will be shown when shared on social media. Fetch from browser.
Control a lunar module and try to land softly on the moon. Manage fuel and thrust. Classic arcade physics. Canvas.
Paste Lottie JSON code or upload a .json file and see the animation play. Control speed and loop. Perfect for developers.
Simulate how images and UI elements appear to users with various types of color blindness. Upload or paste image URL. Promote inclusive design.
Flip a virtual coin to make a decision or settle a dispute. Realistic animation and fair random outcome. Simple, fast, and always available.
Simulate rolling dice for board games, RPGs, and decision making. Choose number of dice and faces. Fun, lightweight, and no download required.