Multi‑User Whiteboard (Local) - Online Shared Drawing
Open the same page in two tabs and draw together in real time using BroadcastChannel API. Share ideas without a server.
UD5 Toolkit
Open the same page in two tabs and draw together in real time using BroadcastChannel API. Share ideas without a server.
Upload a photo and convert it to a pixelated cross-stitch pattern with DMC floss color matching. Adjust size and color count. Local processing.
Rotate and explore the RGB color space as a 3D cube. Pick colors directly from the volume. Interactive Three.js.
A fully animated deck of 52 cards. Shuffle, cut, or draw a specific number of cards. Perfect for missing cards in a real deck.
Overlay a grid on any image to help you draw it freehand. Adjust grid size and line thickness. Useful for artists.
Generate a random sequence of button presses that looks like a retro game cheat code. Totally useless, totally fun.
Reduce an image to large colored squares. Create bold, minimalist wall art. Adjust block size. Download PNG.
Enter a number of sides (3‑100) and get the correct polygon name (triangle, hectogon). Fun geometry reference.
Enter an unbalanced chemical equation and get the balanced coefficients instantly. Supports parentheses and ions. All local JavaScript algebra.
Enter two sides of a right triangle and get the third. Also gives area and perimeter. Simple and visual.
Enter dependencies in a simple text format and see a force‑directed graph of the project's dependency tree. For planning architectures.
Enter your average last frost date and generate a planting schedule for vegetables and flowers. Know exactly when to start seeds indoors or direct sow.
Arrange virtual fabric squares or triangles on a grid to preview a quilt pattern. Change colors and sizes. Export layout.
Create beautiful Spirograph patterns by adjusting circle radii and pen position. Change colors and save as PNG. Relaxing math art.
Align card elements across rows using CSS subgrid. See how headers and footers align vertically. Future of CSS layout.
Get the exact RGB inversion (negative) of any color. Useful for dark mode theming and high‑contrast accessibility checks.
A paint worklet that draws a moving 3D cube. See Houdini in action and copy the JS file. Modern CSS magic.
Create 1-point, 2-point, or 3-point perspective grids. Adjust vanishing points and grid spacing. Useful for artists and architects.
Compress and decompress text using the browser's native Compression Streams API. See the binary output size.
Connect a game controller and see every button press, axis movement, and vibration test. Uses the Gamepad API.
Unified input demo: see pressure, tilt, and type from any pointer. Compare pointerType values. Essential for drawing apps.
Modify the DOM via buttons and see MutationRecords logged. Understand childList, attributes, and subtree options.
Decode an image progressively using the ImageDecoder API. See partial results and metadata. Modern alternative to <img>.
Decode individual video frames from a local file using the VideoDecoder API. Step through frames. Cutting‑edge browser feature.
Register a one‑off background sync and see it fire when connectivity returns. Debug service worker sync logic.
Request permission and detect when the user is idle (away from keyboard). See screen lock state. For native‑like apps.
Acquire and release locks across tabs. Prevent race conditions in IndexedDB or localStorage. Visual queue and lock state.
Read, write, and delete cookies using the modern Cookie Store API. Monitor change events. No more document.cookie parsing.
Connect a gamepad and see all button presses and axis movements visually. Check that every input is detected correctly.
Trigger different vibration patterns on mobile devices. Test if your phone supports haptic feedback. Simple demo.