Contact
One person reads everything sent here. Bug reports are the most useful thing you can send, particularly if a tool gave you a wrong answer. The changelog records new tools, new pages and major rebuilds.
There is no contact form, on purpose. A form needs a server to receive it, and that would be the only server-side thing on this site. An address does the same job without the contradiction.
Reporting a wrong answer
This is the one worth doing properly, because a calculator that is confidently wrong is worse than no calculator. If you can, include:
- which tool, and the page address;
- what you put in;
- what it gave you back;
- what you expected, and why.
That last one matters more than it sounds. A good share of reported bugs turn out to be a disagreement about the rule rather than a mistake in applying it, and knowing which rule you expected is what makes the difference clear. Either way the page gets better: a real bug gets fixed, and a rule that people reasonably expected differently gets explained on the page.
Most tools here have a share button that puts the state in the link, so pasting one is the fastest way to show exactly what you were doing.
Requesting a tool
Worth sending. The roster is planned out for a while, but the plan is a guess about what people want and a specific request from someone who actually needs the thing beats a guess. Tell us what you are trying to do rather than what the tool should be called.
Accessibility problems
Please send these. Automated checks run on every build, but they only catch part of it, and a report from someone actually using a screen reader or keyboard navigation is worth more than the whole audit. These get priority over feature work. What the automated pass does and does not cover is set out in how we build tools.
Before you write about a wrong number
Check the method first. Each calculator explains its method on its own page and says where its figures come from, or says plainly when a figure is only a starting point. So a disagreement is often a difference in rounding or in which source applies rather than a bug. How we build tools covers the general method and the contrast formula, and the correction rules are in the editorial policy. If it still looks wrong after that, it probably is, and it is worth sending.
What happens next
Aaron Wilson reads it. There is no ticketing system, no autoresponder and no support tier. Small fixes usually happen in a day or two. Larger ones take longer. The changelog records new tools, new pages and major rebuilds, so you can see when a larger change landed without waiting for a reply.
Last updated . The changelog lists what changed across the site, and when.