Trust and rights
What this site does not collect
There is no account to make, and this service stores nothing that identifies you. Google Analytics and Google’s advertising tags are the exception, and you choose what they may do below. Everything else is enforced by the code rather than promised by this page.
Not collected by this service
None of these exists anywhere in this service.
No accounts
Nothing to sign up for, so there is no name, no password and no profile.
No cookies of our own
The site sets none. The cookies a reader may receive are Google’s, under the choices below.
No profile kept here
A session key and any lesson draft live in sessionStorage and die with the tab.
No IP addresses
This service stores none with any event, and uses none to identify a reader.
Stored only in this tab
Stored by your browser, never sent to this service.
Lesson drafts
When you edit a minimal lesson, its title, objective, prompts, member choices and optional teacher note are kept in sessionStorage. The draft is scoped to that comparison, review date and member set, so it can be restored after you visit the comparison and come back.
The draft never leaves the browser, is unavailable to another tab, and is deleted when the tab closes or when you choose “Discard saved draft”.
What is recorded, and for how long
Two things are recorded, both deliberately shallow.
Product events
Which surfaces get used — a search happened, a comparison was opened, a lesson was copied. The route accepts only the ten names in an approved vocabulary and rejects any property outside a strict allow-list, so a search query cannot be recorded even by accident. Events carry a session key that exists only for the life of the browser tab.
Deleted after 90 days at the most, and the purge job refuses a longer window than that.
Issue reports
When someone reports a mistake, the report carries the record it is about, a reason, and whatever explanation they chose to write. It collects no identity — no name, no email, no address — and returns an anonymous reference, which is the only thread back to it.
The free text is redacted after the report is closed; the structured reason is kept, because that is what makes a pattern of complaints visible. Submitting a report does not change the reported page immediately, and we cannot send a personal follow-up because no contact detail is collected.
Google Analytics and advertising
What Google may do here, and your choice about it.
Every page loads Google Tag Manager, which runs Google Analytics and, if they are added, Google’s advertising tags. Analytics counts visits, the pages read and how readers arrived, and sets the _ga cookies to recognise a returning browser. Advertising measures ads and sets the _gcl cookies. This site shows no ads today.
In the European Economic Area, the United Kingdom, Switzerland, Turkey and Québec, both are off until you choose, and the banner asks. Until then Google receives only cookieless signals that a page was viewed, which it uses to estimate visits without recognising anyone. Elsewhere both are on by default, and you can turn either off here. If your browser sends Global Privacy Control, advertising is off, even if you allowed it before, until you turn it on again here. The region comes from the country, and in Canada the province, that our network provider reports for the request; it is not stored.
Google receives your IP address with each request, as any website you load does. Your choice is kept in this browser’s localStorage. Anything you allow lasts twelve months, then returns to the default for your region, and where the banner asks, it asks again. Anything you turn off stays off until you change it, and turning something off deletes what Google stored for it. What Google does with the data it receives is described in Google’s own policy.
Why it is built this way
A product whose argument is that you can check its claims cannot ask you to take its data handling on trust. So this service collects nothing about you itself, and the one outside measurement is Google’s, under a choice you can change on this page. It also costs something real: there is no way to email you when a comparison you read is corrected. That is the trade, made on purpose.
Report an issue is the one channel back to us, and it is anonymous by design.