About Numberdle

Who Makes This

One independent developer, working alone. There is no company behind Numberdle, no team, no investors and no roadmap meeting. I build the puzzle, write the pages, fix what breaks and pay for the hosting.

That has consequences worth being upfront about. Replies to email can take a few days. Bugs that only affect one browser may take a while to reach. If the puzzle ever breaks badly for a day, it breaks for everyone until I notice and push a fix. I would rather say that plainly than imply a support desk exists.

Why It Exists

I wanted a daily puzzle about numbers rather than words — one with a bit of arithmetic reasoning in it, where narrowing down a range feels like actual deduction rather than vocabulary recall. The piece I most wanted was the rarity rating: a reason to care about which number came up on a given day, not only how fast it fell.

A six-digit palindrome shows up roughly once every thousand days. Without the rarity system that is just another Tuesday. With it, it is worth a screenshot.

How the Site Is Built

Numberdle is a static site. There is no application server and no database. The pages are plain HTML generated ahead of time, and the puzzle logic is a small amount of JavaScript that runs in your browser.

The daily number is not stored anywhere. It is computed from the date using a fixed hash function, so your browser works it out on the spot and arrives at the same answer as everyone else’s. That is what lets the whole thing run with no backend, and it is also why past puzzles can be replayed — the same function run on an older date reproduces that day’s number exactly. The explainer on randomness and fairness goes into how that works and why it is not as circular as it sounds.

What It Costs and What It Collects

The game is free, with nothing to unlock and nothing to buy. The running cost is a domain name and static hosting, which is cheap enough that I cover it myself.

There are no accounts, so there is nothing to sign up for and no password to lose. Your streak, your guess history and your best results are kept in your browser’s local storage — on your device, readable only by you, never transmitted to me. I cannot see your scores. If you clear site data for numberdle.com, that history is gone for good, and I have no copy to restore.

At the time of writing there are no third-party analytics scripts, no advertising scripts and no tracking pixels, which is why you were not asked to dismiss a cookie banner on the way in. If that changes, this page will say so.

Getting in Touch

Bug reports are genuinely useful, especially ones that name your browser and describe what you expected to happen. Suggestions are welcome too, though I will not get to most of them. The contact page has the email address.

Otherwise, the useful links: today’s puzzle, the rules and some tips, and the blog.