The calculations designers keep doing by hand.
Colour conversion, proportional scaling, grids, picas, copyfitting and the characters everyone gets wrong. Free, instant, and none of it leaves your browser.
Colour Tools
Six tools that all work in OKLCH under the hood. That matters more than it sounds: OKLCH is perceptually uniform, so a midpoint looks like a midpoint and a hue rotation keeps every colour at the same visual weight. Tools built on HSL and raw hex cannot do either, which is why their gradients go muddy and their palettes have one colour that jumps out.
- Colour ConverterEvery format for one colour, including OKLCH.
- Contrast CheckerFive WCAG checks with a live preview of the actual text.
- Colour Blend GeneratorSmooth ramps between two colours that keep their saturation.
- CSS Gradient GeneratorCSS gradients in both spaces, shown side by side.
- Colour Palette GeneratorTints, shades and harmonies that hold together.
- Colour Blindness SimulatorHow your colour pair reads to everyone else.
Layout & Measurement Tools
The calculations that used to live on a wheel in a desk drawer, or on a laminated card pinned above the desk. Proportional scaling, picas to millimetres, how much space a given amount of copy will take, and where the columns fall on the page. None of them are difficult; all of them are tedious, and all of them are easy to get subtly wrong at eleven at night.
- Fraction and Unit ConverterDecimals to fractions, and every typographic unit.
- Proportional Scale CalculatorThe percentage, the new size, and whether it crops.
- Page Grid CalculatorColumns, margins and baselines, drawn to scale.
- Copyfitting CalculatorHow deep your copy runs, and whether the measure works.
- Special Character ReferenceSeventy characters, and when to use each.
Built the way the work is actually made.
Perceptual colour throughout
Every blend, palette and gradient is computed in OKLCH. That is why the middle of a gradient here does not turn to mud, and why a harmony set does not have one colour that glares.
Honest about its limits
CMYK without a profile is an approximation and says so. A copyfit is an estimate and says so. A tool that hides its assumptions is harder to trust, not easier.
Nothing leaves the browser
No account, no analytics, no server. Every calculation runs on your machine, which is the only version of privacy that means anything.