
Match a heading and body font with real Google Fonts pairings and scale steps.

Every text and background pair scored against WCAG AA and AAA for normal and large text.

Build a linear, radial or conic gradient stop by stop with position sliders, then copy the CSS — which is re-parsed on the page to prove the output is valid.

Design a button's colours, padding, radius, border and shadow with a live preview, and get a measured WCAG contrast verdict on the text.

Draw random whole numbers in any range, with unique and sorted modes and a cryptographic source.

Convert 1-3999 both ways, see how each numeral adds up and catch non-standard forms like IIII.

Test any number for primality with Miller-Rabin, then get its prime factorisation and every divisor.

Mean, median, mode, quartiles, range and standard deviation for any list of numbers.