Privacy

Last updated: October 8, 2026

Guessmint collects only what it needs to run the game, to understand in general terms who plays it, and to make the game better. This page says what that is, and what we would do first if it ever grew.

What stays on your device

The game remembers you with your browser's local storage, not with an account. It keeps your guesses for the current day and the two weeks before it (older days are cleared), your streak and the number of games you've played, and your settings: kilometres or miles, how your tries are ordered, and whether you've closed the how-to-play note. None of it is sent to us. Clearing your browser's site data removes it, and it doesn't follow you to another device.

Browsers often list local storage under "cookies and site data", so Guessmint may appear there. It isn't a cookie: nothing in it travels with your requests, and we can't read it.

No accounts, no profiles

There are no accounts to sign up for. Guessmint itself sets no cookies and includes no social-network buttons or advertising trackers. We don't build a profile of you, and we don't sell or share anything about you with advertisers or data brokers.

What we record about visits

To understand where players are and what they play on, we record basic technical information about visits: an approximate location (country and region) worked out from your IP address, and your type of device, browser and operating system, read from the information your browser sends with every request (its user agent). We look at this in aggregate — how many players are in each country, how many play on a phone — and we don't use it to identify you.

We also use Cloudflare Web Analytics to count page views. It doesn't use cookies or local storage.

Reporting a mistake

If you tell us something is wrong with a coin, the report is a fixed choice from a short list — which part of the coin, what kind of problem, and sometimes a suggested correction — and nothing you type. We store the choice with the day's coin. To count each problem once per household, we also keep a scrambled form of your network address for that day (a one-way code that changes every day and that we cannot turn back into the address), and we clear it two days later. Reports are read by us, and the totals may be shared with the museum or archive that supplied the photograph.

Trying out changes to the game

From time to time we may try a change — a new game mode, a different layout — with some players before everyone, and compare how the rounds go. If we do, it will be done without associating anything with you as a person: no account, no name or email address, nothing that identifies you or follows you between sites. What we look at is how the versions compare across everyone who played them, not what any one player did.

How Guessmint pays its way

Guessmint carries no advertising. If it ever does, it will be the kind that doesn't need to know who you are, such as a sponsor's message chosen by us and shown to everyone, or a referral link to a coin dealer, a bookshop or a museum shop that pays us a small commission when you buy something through it. Such a link tells the other site that you came from Guessmint, not who you are, and it tells us nothing about you.

Our host

Guessmint runs on Cloudflare. Like any website, delivering a page means handling your IP address and browser information for the request; Cloudflare also uses them to protect the site from abuse, such as automated floods of requests. If Cloudflare needs to check that a visitor is a person rather than a program, it may set a short-lived security cookie on guessmint.com (named __cf_bm or cf_clearance) so it doesn't have to ask again. That cookie exists only for the check: the game doesn't read it, and it isn't used to track you.

Links to other sites

After a round, the image credit links to the museum or archive where the photograph comes from, and other pages may link to shops or references. Those sites have their own privacy policies.

Changes to this page

If what Guessmint collects changes, this page changes first, and the date at the top moves.