Colour Converter
Paste a colour in any of the common notations and read it back in all the others, with the channels, the nearest named colour and the contrast ratio against white and black. Alpha is carried through the whole conversion, so a translucent colour does not quietly become opaque.
For the HSL and HSV percentages.
Used when the text box is empty, so you can pick a colour visually.
How colour converter works
- Paste a colourAny of the four notations, or use the picker when the box is empty.
- Read every notationHEX, RGB, RGBA, HSL, HSLA and HSV, with alpha preserved.
- Check the contrastThe ratio against white and black, with the AA verdict for body text.
What you get
Convert HEX, RGB, HSL and HSV in both directions. Everything happens inside this page: the file is read by your browser, transformed in memory and handed straight back to you as a download. There is no upload queue, no waiting for a server, and nothing left behind when you close the tab.
Supported formats
This tool works on text you paste or type, so there is no file format to worry about. Nothing you type is sent anywhere.
Limitations, stated up front
- sRGB only. Wide-gamut values, and any conversion between sRGB, Display P3 and Rec. 2020, are out of scope.
- Named colours are a short common list rather than the full CSS set, so an unusual colour will be reported as nearest to a coarse approximation.
Frequently asked questions
What is the difference between HSL and HSV?
Both are two-dimensional ways of describing a colour with a hue, and they differ in what the two numbers mean. In HSL the second number is lightness, where zero is black and full is white. In HSV it is brightness, where full is fully saturated colour, so pure red is full and a pale red is also full at lower saturation. HSL is what CSS uses; HSV is what design tools show, because a saturation and brightness slider feels more predictable.
Why does the contrast figure ignore transparency?
Because contrast depends on what is behind the colour, and Furtu cannot know that. A half-transparent black over white and over black give completely different results. Use the opaque value for the calculation and check the composite by eye.
Is the nearest named colour the same colour?
No, unless it says the match is exact. A named colour is a fixed point in a continuous space, so “nearest” is a distance in RGB and can still be visibly different. It is a useful label for communication — the blue one — and a bad source for a specification.
Which colour space is this?
sRGB, because that is what every screen and every browser uses unless it is told otherwise. Wider-gamut spaces hold colours sRGB cannot, and converting between them changes the numbers; Furtu does not claim to do that.
Is anything sent when I convert a colour?
No. It is arithmetic on three numbers, performed in your browser. There is nothing about a colour worth sending, and nothing is sent.