Privacy Policy

This Privacy Policy applies to RREF Calculator (rref-calculator.org) and related pages. The site provides online tools for reducing matrices, calculating reduced row echelon form (RREF), reviewing row-operation steps, and learning linear algebra.

Our Approach

We try to collect only what is needed to operate and improve the site. Matrix values entered into the calculator are primarily processed in your browser to generate RREF results, step-by-step explanations, and copyable LaTeX or text output. We do not require user accounts, and we do not sell your personal information.

Information We Collect

Information You Provide

Matrix input and calculator settings: matrix dimensions, cell values, random matrix choices, and example matrix selections used to complete calculations on the current page.
Email address: when you subscribe to the newsletter, unsubscribe, or contact us by email.
Submitted content: if a feedback, product submission, or similar form is available, we process the text, links, and contact details you submit so we can review and respond.

Information Collected Automatically

In production, the site may use Vercel Analytics, Google Analytics, Baidu Tongji, Plausible Analytics, and Google AdSense. These services may collect:

pages visited, referrers, clicks, and session events;
device type, browser, operating system, language, and approximate region;
IP address or anonymous/aggregated identifiers generated by the provider;
ad impressions, ad interactions, and ad performance data.

We use this information to understand whether pages work well, which calculator pages are most useful, how to improve the content, and how to support the operation of the site.

Matrix Calculation Data

The core RREF calculation runs in your browser. Matrix input is used to produce results and steps; it is not tied to an account or stored as a user profile. Some features may encode matrix data into a shareable URL, such as a solved matrix page. Anyone with that URL may be able to view the matrix contained in it. Do not enter sensitive personal information, confidential data, or protected student records into matrices, URLs, forms, or emails.

Cookies and Similar Technologies

We and third-party services may use cookies, local storage, or similar technologies to:

remember language, theme, or interface preferences;
measure site usage and performance;
detect abuse and limit excessive requests;
show, measure, and improve advertising.

You can delete or block cookies in your browser settings. Some features may not work correctly if cookies or scripts are disabled.

When you subscribe to the newsletter, we use your email address to send welcome emails, updates, or content related to RREF Calculator. We use an email service provider to manage the mailing list and deliver messages. Subscription emails should include an unsubscribe option when applicable; you may also unsubscribe through the site or contact us directly.

Third-Party Services

We may use these categories of third-party services:

Hosting and infrastructure: to serve the site, keep logs, monitor performance, and troubleshoot errors.
Analytics services: to understand aggregated usage and improve the page experience.
Advertising services: Google AdSense may use cookies or advertising identifiers to deliver and measure ads.
Email services: to manage newsletter contacts and send emails.

These third parties process data under their own privacy policies. We do not control every data-processing activity that occurs on third-party platforms.

How We Use Information

We use collected information to:

provide matrix calculation, step display, copy, and sharing features;
maintain site security, stability, and performance;
improve the calculator experience, documentation, and localized pages;
send requested subscription emails or respond to contact requests;
prevent abuse, spam submissions, and excessive request rates;
meet applicable legal, compliance, or security requirements.

Data Retention

Matrix input in the browser is usually retained only in the current session, page state, or a shareable URL you create. Analytics, advertising, log, and newsletter data are retained by the relevant services for reasonable periods depending on service configuration, legal requirements, and operational needs. After you unsubscribe, we make reasonable efforts to remove your email address from the mailing list.

Data Security

We use reasonable technical and organizational measures to protect the site and related data. However, internet transmission and third-party services cannot be guaranteed to be completely secure. Avoid entering sensitive information into the calculator or publicly shareable links.

Children's Privacy

The site is intended for students, educators, and general users learning linear algebra, but it is not designed to knowingly collect personal information from children. If you believe a child has provided us with personal information, contact us and we will make reasonable efforts to address or delete it.

Your Choices and Rights

You may:

avoid submitting email or form information;
delete or restrict browser cookies;
use browser or advertising-platform controls for personalized ads;
unsubscribe from the newsletter;
contact us to request access, correction, or deletion of personal information you provided to us.

Contact

For privacy questions, email: [email protected].

Updates to This Policy

We may update this policy as site features, analytics tools, advertising configuration, or legal requirements change.