Privacy policy
Effective November 6, 2026
math.wiki is run by NUDGELEARN LLC, 9 Van Riper Ave, Montville, NJ 07045, USA ("we"). This page says what we collect, why, who handles it for us, and how to have it removed. Questions: support@math.wiki.
Reading lessons: no account, no cookies
Anyone can read math.wiki without signing in. We do not set cookies for readers. We count page views with Microsoft Application Insights and Google Analytics, both set up to store nothing in your browser. They see the page you opened, the page you came from, your browser type, and a rough location from your IP address. We use this only to see which pages are used and to find errors. We do not sell it or use it for ads.
If you arrive from a link with campaign tags (such as utm_source) or from another website, your
browser keeps that source and the first page you opened in its session storage, named mw_src. It is
not a cookie, it is not sent anywhere while you read, and it is gone when you close the tab. If you then make an
account or buy something, we record that source with it, so we know which links bring teachers here.
If you arrive from a Microsoft (Bing) ad, Microsoft adds a click ID to the link (msclkid), and we keep
it the same way. If you then buy something, we send Microsoft that click ID with the time and amount of the
purchase, so Microsoft can tell us which ads lead to sales. We do not send your name, email or anything else, and
we do not put a Microsoft tracking tag or cookie on this site.
Teacher accounts
Accounts are for teachers and other adults who teach math. They are not meant for children, and students do not need an account to read the site. If you sign in, we keep:
| What | Why |
|---|---|
| Your email address | To identify your account and to send sign-in codes. |
| Your name, if Google or Microsoft shares it or you type it | To greet you and to print on sheets you download (see below). |
| Which sign-in you used (Google, Microsoft or email code) and that provider's account ID | To recognise you next time. |
| Where you came from when the account was made or a purchase was paid: a link's campaign tags or the site that linked here, and the first page you opened | To see which links and sites bring teachers to math.wiki. |
| Your plan, course passes and the sheets you opened, with dates | To give you what you paid for and to count your monthly items. |
| Sign-in sessions: when they started, your browser type, and a scrambled (hashed) form of your IP address | To keep you signed in and to stop abuse. We never store your raw IP address. |
When you sign in with Google or Microsoft we ask only for your basic profile: email address, name and an ID. We never see your password, and we get no access to your mail, files or contacts.
Your name on downloaded sheets
Every worksheet, quiz, test and key you download carries a line at the bottom with your name and email address, saying the sheet is licensed to you for classroom use. Anyone you give the file to can see that line.
Classes and grades
If you use the free classroom and gradebook, we store what you type into it: class names, your students' names, assignments and scores. Only you can see them, through your account. We ask for names only: please do not enter student emails, ID numbers or other details. Deleting a class deletes its names and scores at once; deleting your account deletes all your classes. We never use this data for anything except showing it back to you.
Cookies we set
| Cookie | What it does | How long |
|---|---|---|
mw_session | Keeps you signed in. | 30 days, or until you sign out |
mw_oauth | Protects a Google or Microsoft sign-in while it is in progress. | Minutes |
Both are set only when you sign in. Neither is used for tracking or advertising.
Payments
Paid plans are billed by Stripe. Card details go straight to Stripe; we never see or store your card number. We keep what Stripe tells us about your plan (which plan, when it renews or ends).
Who handles data for us
- Microsoft Azure (United States): hosting, database, file storage, page-view counts and the email that sends sign-in codes.
- Google: Google sign-in, if you choose it, and Google Analytics.
- Microsoft: Microsoft sign-in, if you choose it.
- Stripe: payments, if you buy a plan.
Each handles the data only to provide its service to us. We do not sell or rent personal information, and we do not share it with advertisers.
How long we keep it
Sign-in codes expire after 10 minutes. Sessions end after 30 days or when you sign out. Account data stays while you have an account. If you ask us to delete your account, we delete your account data within 30 days, except records we must keep for tax or accounting (such as payment records).
Your choices
Email support@math.wiki from the address on your account to see what we hold about you, to correct it, or to delete your account. You can change the name printed on your sheets on your account page at any time.
Changes
If we change this policy we will update the date at the top. If a change matters to account holders, we will also email them.