Privacy and affiliate disclosure

The short version: DisplayMath collects no personal information, the site counts visits without cookies, and some store links may earn a commission.

No personal information

DisplayMath has no accounts and no sign-up, and never asks who you are. The resolutions, sizes and distances you enter are screen specifications, not personal information, and every calculation runs in your browser. Each visit starts fresh: the calculator does not keep your setup between visits. While you work, the calculator also writes your setup into the page's address, so that a copied link shows exactly the same comparison to anyone you send it to. That address, including any name you give a card, is what a shared link carries and what the augmented reality preview described below sends, so keep card names to screen names rather than anything private.

Analytics without cookies

To learn which features are used, the site loads two lightweight analytics scripts: a self-hosted Umami instance at stats.displaymath.com, and Ahrefs Web Analytics. Neither sets cookies, neither builds a profile across sites, and both aggregate page views and clicks rather than identifying people. Umami additionally records which controls are used, such as switching a canvas view or opening a store link. Umami records page addresses without their query string, so the setup the calculator writes into the address never reaches it. Ahrefs records the address a visit lands on, which for a shared link includes the comparison it encodes, but not the edits made after that. IP addresses are used only to derive a country and are not stored in the reports.

Requests the site does make

Hosting and delivery. The site is served through Cloudflare, which sees the requests any web server sees. The site reads the visitor's country from Cloudflare's headers once per visit, to choose default units (inches or centimetres) and which store a price link points to. The country is not stored.
Augmented reality previews. On an iPhone, the "See on your wall" and measuring-tape features request a small 3D model from DisplayMath's own server, with the screen dimensions and the card's name, or the tape length, in the request. That request is not logged beyond standard server access logs, which are kept briefly for operational purposes.
Fonts and scripts. Everything else the pages need is served from displaymath.com itself. There are no embedded social widgets or advertising tags.

Affiliate links

Some cards and comparison pages show one "See price" link for a screen that matches a preset. For most visitors it opens a search on Amazon; for visitors in Romania it opens a search on eMAG. These links are, or are intended to become, affiliate links: DisplayMath has applied to the Amazon Associates program and to Profitshare, the affiliate network that serves eMAG. Once a program accepts the site, following one of its links and making a purchase may earn DisplayMath a small commission from the store, at no extra cost to you, and the required statement (for Amazon: "As an Amazon Associate, DisplayMath earns from qualifying purchases") appears on every page that carries such a link.

Following one of these links takes you to the store's website, which has its own privacy policy and may set its own cookies to attribute the sale. DisplayMath receives no information about who you are or what you bought; at most, it receives an aggregate count of orders and the commission owed. Affiliate links are marked as sponsored in the page's HTML, and a note beside the link says which store it earns from. Commissions never influence which screens are recommended or how any number on the site is calculated; see About DisplayMath.

Email

If you write to hello@displaymath.com, the message is kept for as long as it takes to answer it and act on it, and is not added to any list. There is no newsletter.

Children

The site collects no personal data from anyone, so it collects none from children. It is a calculator, not a service that needs to know who is using it.

Your rights and changes to this page

Because DisplayMath stores no personal data, there is nothing to access, correct or delete on its side. If the site ever starts collecting more than described here, this page will say so before it does, with the date below updated. Questions about any of this go to hello@displaymath.com.