Tool
What the LAB Color Converter does
LAB Color Converter: converts CIELAB, HEX and RGB from Pick a colour.
Point it at Pick a colour and it returns CIELAB, HEX and RGB. Results refresh instantly, so trying variations costs nothing but a moment.
Contrast failures are the most common accessibility problem on the web, and the easiest to fix. That is usually what brings anyone checking a colour for legibility here.
This runs client-side, which means we never receive what you enter and could not retrieve it if asked.
The sections that follow cover the fields, the method, and one full example computed from the defaults.
What do the LAB Color Converter fields mean?
The LAB Color Converter uses 1 input. Every field is populated on load; treat those numbers as a template rather than a suggestion.
| Field | What to enter | Default |
|---|---|---|
| Pick a colour | optional | #2563eb |
How does the LAB Color Converter work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same conversion.
Checks happen up front, so errors surface next to the form instead of hiding in the output.
What a typical run looks like
You provide: Pick a colour
What happens: the file is read into memory by your browser, processed locally, and offered back as a download. It is never uploaded.
You get back: a processed file plus a short status summary in the tool panel.
The tab does the processing, so speed tracks your hardware and very large files fail on memory rather than on a quota.
CIELAB: perceptually uniform
CIELAB was designed so that equal numerical distances correspond to roughly equal perceived differences. RGB and HSL have no such property, which is why colour difference calculations use Lab rather than either of them.
| L* | 0 to 100 | perceptual lightness, 0 black, 100 white |
|---|---|---|
| a* | −128 to +127 | green to red |
| b* | −128 to +127 | blue to yellow |
| Gamut | Larger than any display | device-independent |
Worth knowing
- Delta E, the distance between two colours in Lab space, is the standard measure of colour difference. A Delta E under about 2.3 is generally imperceptible to most observers.
- Lab is device-independent, which is why colour management systems use it as the connecting space between a scanner, a monitor and a press.
- L* is genuinely perceptual, unlike HSL lightness. L* 50 looks mid-grey regardless of hue.
- Lab can express colours no screen or printer can reproduce, so a round trip through a device gamut is lossy in a way the Lab values themselves are not.
How to use it
- Enter Pick a colour.
- Each keystroke triggers a fresh calculation, which is cheap because it happens locally.
- You get CIELAB, HEX, RGB, HSL and CMYK back.
- Share the link rather than a screenshot. It carries the values with it.
What this tool does not do
- Conversions between colour spaces with different gamuts are approximate at the edges.
- Colours render differently across displays; the values are exact but the appearance is not guaranteed.
- Results are informational: check anything consequential against a second source.
Frequently asked questions
One thing: Pick a colour. Each field is pre-filled with a sensible default, which makes it easy to isolate the effect of a single variable.
It is not stored or transmitted. The calculation happens locally and leaves no trace with us.
It is free to use, with no premium tier holding back the useful parts.
It implements the published definition directly, without shortcuts or approximations.