The same colour has several addresses. Hex and RGB describe the same thing in different notation; HSL rearranges it into hue, saturation and lightness, which is easier to reason about when building a palette; OKLCH goes further and spaces the values the way the eye actually perceives them, so equal steps look equal. Converting between them is exact in one direction and lossy in another — anything leaving a wider gamut for a narrower one has to give something up, and these tools say when that happens.
Tools in this category
HEX to RGB
Convert a hex colour to its red, green and blue channels, including the shorthand and alpha forms defined by the CSS specification.
RGB to HEX
Turn red, green and blue channel values into the hex code stylesheets expect, with alpha where you need it.
HEX to HSL
Convert a hex colour into hue, saturation and lightness — the form that makes a colour easy to lighten, darken or desaturate by hand.
HSL to HEX
Turn hue, saturation and lightness into a hex code — useful when a colour was picked by feel and now has to go into a stylesheet or a design file.
RGB to HSL
Convert red, green and blue channels into hue, saturation and lightness, the form that says what a colour actually is.
HSL to RGB
Convert hue, saturation and lightness into the red, green and blue channels a screen actually uses.
HEX to OKLCH
Convert a hex colour to OKLCH, the perceptual colour space where equal changes in lightness actually look equal.
OKLCH to HEX
Turn an OKLCH colour into a hex code for tools that do not speak modern colour syntax yet.
Suggest a tool
Tell us what is missing and where its numbers should come from.
What should it convert, calculate or generate, and where would the authoritative numbers come from? A link to the standard or publication that defines them is the most useful thing you can send.
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How these tools are built
Every tool in this category runs entirely in your browser: there is no upload, no account and no request to a server once the page has loaded. The numbers behind them are transcribed from the organisation that defines them — NIST for units, the W3C for web formats, the WHO for health measures — and each page names its source next to the formula. A tool whose reference values stop reproducing fails the build and does not ship, which is the whole reason the catalogue grows slowly.