Tool
What the Delta-E Calculator does
Delta-E Calculator: calculates ΔE (CIEDE2000) from Colour A and Colour B.
Give the Delta-E Calculator your Colour A and Colour B and it works out ΔE (CIEDE2000). Everything recomputes live, which makes it easy to test a few scenarios in a row.
Picking colours that work together is easier with the maths already done. The Delta-E Calculator exists to take that particular chore off your hands.
Your data stays on your machine. Once the page has loaded you could disconnect entirely and it would still work.
The field table, the method and a worked example are documented after the tool for anyone who wants to check the working.
What do the Delta-E Calculator fields mean?
The Delta-E Calculator uses 2 inputs. It opens with a complete example loaded, which is usually the quickest way to understand what a field means.
| Field | What to enter | Default |
|---|---|---|
| Colour A | optional | #2563eb |
| Colour B | optional | #3b82f6 |
How does the Delta-E Calculator 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 calculation.
If something is off you are told which field, not given a generic failure.
What a typical run looks like
You provide: Colour A and Colour B
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 new file plus a brief account of what happened to it, shown in the panel.
How long this takes is a property of your computer, not of our infrastructure, and file size is bounded by browser memory.
Read next: Colour Contrast and WCAG: The Ratio, the Thresholds, What They Miss
How to use it
- Set Colour A.
- Put Colour B.
- Results update continuously rather than on submit.
- Check ΔE (CIEDE2000) on the right.
- To keep the result, either copy the link or print the page. Both preserve what is on screen.
What this tool does not do
- Colours render differently across displays; the values are exact but the appearance is not guaranteed.
- Conversions between colour spaces with different gamuts are approximate at the edges.
- There is no history: reload the page and the previous run is gone.
Frequently asked questions
Colour A and Colour B, nothing else. Defaults are loaded for all of them, so nothing is mandatory before you see a result.
No. Your browser is doing the computing, so we could not see the values even if we wanted to.
It is free with no conditions: no sign-up, and no limit on how often you use it.
The formula is shown above precisely so you do not have to take the accuracy on trust.