Summary
- Matrices you enter in the calculators are processed only in your browser. They are never sent to us.
- We do not use analytics, advertising, social-media plugins or tracking of any kind, and we set no cookies.
- Our web server keeps standard access logs, including IP addresses, for 14 days for security and operation.
- If you use the contact form, we store your name, email address and message for up to 12 months to reply to you.
- We do not sell or share personal data.
Who is responsible
In this policy, “we” and “us” mean the operator of rrefcalculator.io, which is responsible for the personal data described here. You can contact us about privacy through the contact form by choosing “Privacy request”.
What we collect and why
Calculator input
The RREF calculator and the augmented matrix calculator run entirely in your browser. The values you type or paste, the results and the row operations are not transmitted to our server, not stored in your browser and not included in any web address. Reloading the page clears them.
Server access logs
Like almost every website, our web server records each request it receives: your IP address, the date and time, the page or file requested, the response status and size, the referring page, and your browser's user-agent string. We use these logs to keep the site secure and working, for example to investigate errors or abuse. They are deleted automatically after 14 days. We do not combine them with other data or use them to build profiles.
Contact form
When you send a message, we store your name, email address, chosen subject, message and the date it was received. We use them only to read and answer your message and to handle any request you make. We process them because you ask us to and give your consent in the form; you can withdraw that consent at any time by asking us to delete your message. Messages are deleted automatically after 12 months.
To block spam, the form uses a hidden field, a signed timestamp and a limit on submissions from one IP address. Your IP address is held only in the server's memory for up to one hour for that limit. It is not saved with your message.
Cookie choice
If you answer the cookie banner, your choice and the date you made it are saved in your browser's local storage, not in a cookie, so the banner does not appear on every page. This record stays in your browser and is never sent to us. See the cookie policy.
Cookies, analytics and third-party services
rrefcalculator.io sets no cookies and uses no analytics, advertising, tag managers, embedded videos, social-media buttons, external fonts or other third-party scripts. All pages, styles, scripts and images are served from our own server. The site's security policy blocks resources from other websites.
Some guides link to external sources, such as Texas Instruments and the University of Texas at Austin. When you follow those links, the other website's own privacy policy applies.
Where data is stored and who can access it
Server logs and contact messages are stored on the server that hosts rrefcalculator.io. They are accessible only to the site operator. Contact messages are saved in files that only the contact service can read. We do not sell, rent or trade personal data and do not share it with third parties, unless the law requires us to disclose it.
The server infrastructure is provided by a hosting company, which processes data only as needed to run the server.
Security
All pages are served over encrypted HTTPS connections. Contact messages are stored with restrictive file permissions, and the contact service runs with limited system privileges. No method of storage or transmission is completely secure, but we take reasonable steps to protect the data we hold.
How long we keep data
| Data | Kept for |
|---|---|
| Calculator input | Not collected |
| Server access logs | 14 days, then deleted automatically |
| Contact messages | Up to 12 months, then deleted automatically, or sooner on request |
| IP address for the contact-form limit | Up to 1 hour, in memory only |
| Cookie choice (local storage) | In your browser until you clear it; we ask again after 12 months |
Your rights
Depending on the law that applies to you, you may have the right to:
- ask whether we hold personal data about you and receive a copy of it;
- have inaccurate data corrected;
- have your data deleted;
- object to or ask us to restrict how we use your data;
- receive your data in a portable format;
- withdraw consent at any time, without affecting processing that already took place;
- complain to the data protection authority in the country where you live or work.
To make a request, use the contact form, choose “Privacy request” and describe what you would like us to do. To find a contact message, we will need the email address you used. We may ask for information to confirm the request comes from you.
Children
The site is an educational tool that anyone can use without an account. We do not knowingly collect personal data from children. If you are under the age at which you can consent to data processing where you live, please ask a parent or guardian before using the contact form.
Changes to this policy
If the way we handle personal data changes, for example if we add a new service, we will update this page and the date at the top before the change takes effect. If a change requires your consent, we will ask for it.