Privacy

No cookies, no account, no advertising. Your progress stays in this browser. The site counts how the lessons are used, with no ID stored in your browser, and you can switch that off below.

In this browser

No cookies, from this site or anyone else. This browser's storage keeps these, and nothing else:

lx.progress.v1: Your progress: medals, cleared lessons, Daily results and streak, best Rush, and the lesson and step you are in, so a reload goes back to it. Never sent anywhere.
lx-sound: The sound level you picked (Music, Notes only or Off). Nothing is kept until you pick one. An older lx-muted setting is moved into it.
lx-calm: Whether calm mode is on.
lx.noevents: That you switched usage events off, if you did (or back on, when your browser sends Global Privacy Control).
lx.t: A test that storage works: written and removed again at once.

For as long as this tab is open (session storage, gone when you close it):

lx.active: How long you have played in this tab, so a reload doesn't restart the count for the place-to-stop note.
lx.stop: That the place-to-stop note was shown in this tab.
lx.chooser: That the sound choice was offered in this tab.

The progress page shows your progress, copies it to another browser, or clears it.

Why we measure

To see what works: which lessons people finish, where they get stuck, and whether the Daily brings them back, so we can make the lessons better. Running and improving a free site is our legitimate interest, and we measure no more than that needs.

What is measured

The lesson pages send short events to this site's own server while you play:

the page loading, and your first key press or tap
which sheet and step comes into view and how you got there (a link, a sheet tab, Next, New sheet or Fresh sheets), and whether a lesson was picked up where you left it
right and wrong answers: for a right one, how long the step took, how many keys you pressed against the par, whether you used the mouse or Show me, how many tries it took, its medal, and whether you used another function than the one taught; for a wrong one, why it was refused; with either, the formula, as below
Show me, and on which step
a lesson cleared: its medals, how long it took, and why its medal isn't higher
the Daily sheet: its number, whether it is an earlier day's, the lesson it comes from, its medals, hints used and time, and sharing or copying the result and whether that worked
Rush runs: points, right answers, misses, how the run ended and how long it lasted
changes to the sound level, calm mode and zoom
the note that it's a good place to stop, with the minutes played in that page view (whether the note appears depends on this tab's earlier play)
when the page goes out of view, how long it was visible in total, and on which step

Every event also carries the time since the page loaded, the sheet in view and its setting.

With a right or wrong answer comes the formula typed into that step's answer cell, if it starts with =. Text in quotes is blanked, and so is every word that isn't a function name, a cell reference or a number, so a name or an e-mail address typed into a formula isn't kept. It is cut to 80 characters. Nothing else you type is sent.

Each batch of events also carries these facts about the page view:

a random page-view token, held in memory only and new on every page load, so the events of one page view can be read together
the page address, without anything after a ?
the number that picked the sheets' data, left out on a class link (an address with ?seed= in it)
whether it is a touch screen
the window's width, as small, medium or large
whether the keys are labelled for a Mac
whether the address is a class link, where everyone gets the same sheets
whether your system asks for reduced motion
the first two letters of your browser's language
the name of the site that linked here, never the page itself, and not even the name when it is a numeric address or a local name
a ?ref= tag in the link you followed, such as share
the browser family (Chrome, Safari, Firefox, Edge or other), worked out by our server
the operating system family (Windows, Mac, iOS, Android, Linux or other), worked out by our server

The events are stored on our server for up to 365 days, then deleted. No address and no full browser string are stored: the server keeps only the browser and operating system family.

Your medals, the lessons you have cleared and your streak are never sent as such. But what the site offers you follows from your saved progress, so what you do in a visit can show some of it. For example:

the sheet a visit opens on: the home page opens the first lesson you haven't cleared, or today's Daily when it offers that, and a Daily you have finished opens on its result
a lesson you come back to: it opens on the step you reached, and its events say it was picked up there
a Daily step typed from a formula shown on the card earns silver at most, which can show that you haven't cleared the lesson it comes from
where a card's main button takes you: after a lesson, the next one you haven't cleared; after a Daily, its lesson while you haven't cleared it; after a few Rush runs, today's Daily while you haven't played it
New sheet, which is offered on a lesson's first step only when you cleared that lesson before
Rush, which gives you steps only from lessons you have cleared. Its events don't name the lesson a step comes from or carry your formula, but how a step went (keys, time, par, which function) and why an answer was refused can hint at it

Our analytics

When our analytics is switched on, the events are also passed on to our own copy of Umami, an analytics tool we host ourselves, without cookies. What is passed on: each event and its fields, with the page address and its ?ref= tag, the two-letter language, the referring site's name, the lesson's name, and whether it is a touch screen and the width group. The formula is not passed on. For each event passed on our server passes on your address and browser string, and Umami works out from them the country, region and city, the browser, the operating system, the device type, and a visitor code. That code changes when Umami changes its salt, which it does on a schedule. Umami keeps what it worked out, not the address or the browser string. That copy has no fixed period yet: it is kept until we delete it. Nothing goes to an advertising network or a data broker.

Your choices

You can switch usage events off for this browser below. You can also ask us what we hold about you, or ask us to delete it, at hello@a14a.org.

The switch is kept in this browser only. Lessons, progress and everything else work the same either way. If your browser sends Global Privacy Control, events start off, and stay off unless you switch them on here.

Who runs this site

A14A B.V. runs learningxlsx, its server and its Umami. The events are kept to improve the lessons, and are not sold or given to anyone else.

Questions: hello@a14a.org.