LEGO Color Chart & Hex Reference – Online BrickLink Colors
Browse all official LEGO colors with names, years, and hex codes. Sort by hue. Perfect for builders.
UD5 Toolkit
Discover what hue truly reflects your inner self. Fun, fast, and revealing!
10 quick questions · ~2 minutes
Browse all official LEGO colors with names, years, and hex codes. Sort by hue. Perfect for builders.
Generate a pop signal to determine if speakers are wired in phase. Quick stereo test.
Display an astigmatism dial and instructions for self-assessment. Educational, not a medical diagnosis.
Hear a word spoken by browser TTS and type the spelling. Choose difficulty or paste your own list. Great for kids. Local only.
Enter a hex color and get its relative luminance per WCAG definition. Understand why this matters for contrast.
Load a video and visually check if audio aligns with lips. Use frame‑by‑frame stepping. Debug playback issues.
Enter L*a*b* values and see the corresponding RGB and hex color. Useful for advanced color manipulation.
Toggle a screen wake lock to prevent the device from dimming or sleeping. See the lock state and learn the API.
Paste your Accept‑Language header and see which languages your site should serve based on quality values. Internationalization helper.
Test how your page loads under slow, 3G, or offline conditions by intercepting fetch and applying delays. No DevTools needed.
Check current screen orientation and test the lock API. Useful for mobile web apps. Demo with code.
Test the Fullscreen API: request fullscreen on a colored div, detect changes, and copy the JavaScript boilerplate.
Test the Web Share API by sharing text, links, and files directly from the browser. Check compatibility and see example code.
See a random color and type its name. Score based on accuracy. Fun for designers. Local.
Convert hex or RGB to CIELAB L*a*b* values. Understand perceptual lightness and color opponents. Local math.
Check if your browser and display support the wider DCI‑P3 color space. See the difference with a simple test pattern.
Enter any phrase and instantly see if it's a palindrome, ignoring spaces and punctuation. Fun for word nerds.
Explore the RGB color space as a rotatable 3D cube. Pick a color directly from the volume. Drag to rotate. Canvas 3D.
Convert any image into colored ASCII art using divs with background colors. Creates a stunning text‑based replica. View & copy HTML.
Generate random, formatted ID numbers that match pattern rules for various countries. For testing input validation. No real data.
Quickly test if your webcam, microphone, and speakers work correctly. See live video and audio meter. No data sent.
Generate random but realistic‑looking data arrays (users, products, orders) with typos and missing fields. For test robustness.
Simple interactive eye dominance test: hold up a virtual dot and see which eye stays aligned. Educational.
Build an iframe with different sandbox flags and see live which features are blocked. For secure embedding.
Simulate random mouse moves, clicks, or keystrokes to test idle‑timeout logic. Stops when you move the mouse. Dev test.
Paste a test card number to verify Luhn algorithm, identify issuer (Visa, MC), and check length. No real data.
Play left‑only, right‑only, and frequency sweeps to test your speakers or headphones. Quick audio check.
See a live VU meter of your microphone's input level. Test if your mic is working and adjust gain. Privacy‑friendly.
Get the exact RGB inversion (negative) of any color. Useful for dark mode theming and high‑contrast accessibility checks.
Mix two or more colors using subtractive (CMYK‑like) blending. See what happens when you combine real paints. Brush effect canvas.