Solar System Simulator 2D - Online Top‑Down Orrery
Watch the planets orbit the Sun in a top‑down 2D view. Adjust speed and zoom. Distances not realistic; beautiful model.
UD5 Toolkit
Watch the planets orbit the Sun in a top‑down 2D view. Adjust speed and zoom. Distances not realistic; beautiful model.
Generate a realistic‑sounding exoplanet designation (e.g., Kepler‑442b) and a sci‑fi planet description. For worldbuilding.
An on‑screen ruler that measures in pixels, centimeters, and inches. Drag to resize. Handy for UI designers and developers.
Find out how large you can print based on image resolution in pixels. Understand DPI and megapixels.
Find the optimal TV size for your room or the best viewing distance based on screen size and resolution (1080p, 4K, 8K). Simple THX/SMPTE reference.
Enter a CSS value in vw/vh and see the actual pixel size at current viewport. Dynamic resize demo.
Calculate how many vegetable plants fit in a given area using square foot gardening or row spacing. Visual plant grid. Plan your spring garden.
Calculate projector throw distance or screen image size based on throw ratio. Visualize setup. Essential for home theater planning. Local.
Calculate how much fertilizer to add based on desired N‑P‑K ppm and water volume. For hydroponics and soil growers.
Enter current ball size and target to find approx rubber bands required. Fun and satisfying.
Convert diopter strength to approximate magnification and working distance for macro photography.
Input camera sensor, focal length, aperture, distance to get hyperfocal distance and DoF range. Visual chart.
Design a crystal grid by placing crystals on a sacred geometry template. Add notes. Screenshot your layout. Spiritual/art.
Estimate how much agricultural lime or elemental sulfur to add to change soil pH by a target amount. Based on soil type and current pH. Educational.
Rotate a 3D cube on your phone using the Gyroscope API. See angular velocity around each axis. Amazing sensor demo.
Compute the Euclidean distance between two points in 2D or 3D space. Also shows midpoint. Quick geometry helper.
Learn what water is safe (rain, distilled, low PPM) for pitcher plants and flytraps. Visual PPM scale.
Interactive scale showing dB levels of everyday sounds with playable samples. Hearing safety.
Calculate grout needed (lbs or kg) based on tile size, grout joint, and area. Also recommend spacer size. Local estimator.
Perform arithmetic on fractions and get simplified results. Handles mixed numbers and improper fractions. Step-by-step display. Educational and precise.
Calculate how much pure ammonia to add to reach 4ppm for a fishless cycle. Safe start guide.
Calculate the output voltage and resistor values for a voltage divider circuit. Includes schematic. Handy for electronics hobbyists and engineers.
Enter a package name and version range to see all satisfying versions from the registry. Understand ^ and ~.
Enter log pile dimensions to calculate cords and face cords. Also estimate heat content in BTUs by wood species. Local reference.
Type a line and see syllable count as you write. Generate nature-themed prompts. Poetry aid.
Select your OS, IDE, and programming language to generate a complete .gitignore file. No typing required.
Understand how !important behaves inside @layer vs unlayered styles. Interactive example. Avoid common pitfalls.
Calculate probability of k successes when sampling without replacement. Useful for quality control and card games.
Calculate antenna element lengths for a given frequency (or vice versa). Supports 1/4 wave, 1/2 wave, dipole. Useful for ham radio. Local only.
Calculate how long it will take to pay off credit card debt with fixed monthly payments or a payoff goal. Understand interest costs fully.