Custom Audio Equalizer - Online 10‑Band Adjust & Presets
A 10‑band graphic equalizer applied to any audio file or mic input. Save presets. All processing via Web Audio API.
UD5 Toolkit
dBFS
Frequency Spectrum (Low → High)
A 10‑band graphic equalizer applied to any audio file or mic input. Save presets. All processing via Web Audio API.
Interactive scale showing dB levels of everyday sounds with playable samples. Hearing safety.
Calculate the output voltage and resistor values for a voltage divider circuit. Includes schematic. Handy for electronics hobbyists and engineers.
Input camera sensor, focal length, aperture, distance to get hyperfocal distance and DoF range. Visual chart.
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.
Enter tank volume and recommended dose to find exact ml or capfuls needed. Avoid overdosing fish.
Calculate how much fertilizer to add based on desired N‑P‑K ppm and water volume. For hydroponics and soil growers.
Type a line and see syllable count as you write. Generate nature-themed prompts. Poetry aid.
Find out how large you can print based on image resolution in pixels. Understand DPI and megapixels.
Understand how !important behaves inside @layer vs unlayered styles. Interactive example. Avoid common pitfalls.
Enter log pile dimensions to calculate cords and face cords. Also estimate heat content in BTUs by wood species. Local reference.
Calculate grout needed (lbs or kg) based on tile size, grout joint, and area. Also recommend spacer size. Local estimator.
Enter a CSS value in vw/vh and see the actual pixel size at current viewport. Dynamic resize demo.
Calculate how long it will take to pay off credit card debt with fixed monthly payments or a payoff goal. Understand interest costs fully.
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.
Convert diopter strength to approximate magnification and working distance for macro photography.
Perform arithmetic on fractions and get simplified results. Handles mixed numbers and improper fractions. Step-by-step display. Educational and precise.
Calculate corrected (adjusted) age for premature infants based on birth date and due date. Important for developmental milestone tracking. Local only.
Calculate how much pure ammonia to add to reach 4ppm for a fishless cycle. Safe start guide.
Calculate how much water to change weekly to keep nitrates under control. Based on current nitrate level, desired level, and tank volume.
Track your subscriptions, calculate monthly and yearly totals, and find savings by pausing unused services. Local data.
An on‑screen ruler that measures in pixels, centimeters, and inches. Drag to resize. Handy for UI designers and developers.
Enter current ball size and target to find approx rubber bands required. Fun and satisfying.
Based on your calorie goal, get the perfect gram split of proteins, carbs, and fats. Adjust ratios. For fitness and health.
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.
Determine your ideal daily macronutrient intake based on TDEE, goal, and diet preference. Free nutrition planning tool with local computation.
Calculate resistor values for transistor fixed bias or voltage divider configuration. Quick quiescent point analysis.
Create and dispatch custom events with detail. Listen on other elements. Understand pub/sub pattern in vanilla JS.
Enter a package name and version range to see all satisfying versions from the registry. Understand ^ and ~.