A modular scale multiplies the base size by a fixed ratio for each step, so every heading in the design is the same relationship to body copy. Steps shown: h1 = base x ratio³, h2 = base x ratio², h3 = base x ratio, body = base, small = base ÷ ratio.
Convert HSV to RGB, hex and hsl with a round-trip encoder check, relative luminance and a contrast ratio.
See any picture through protanopia, deuteranopia, tritanopia or total colour blindness.
Click any pixel in an image to get its hex, RGB and HSL values, with a magnifier for precision work.
Convert an AVIF picture to PNG in your browser - the file never leaves the page.
Area, perimeter and volume for the common plane and solid shapes, with pi carried at full double precision.
A 50-item bucket list in eight categories. Tick items, watch the percentage move, and keep it across reloads.
How long since a date, counted with real calendar arithmetic: years, months, days, weekday and next anniversary.
Click for energy, buy multipliers and a decaying passive generator, with max-buy and offline credit.
