Privacy policy
Last updated: 14 November 2026
In short: this homepage collects nothing. My learning platform keeps only what it needs to teach your child, and I never sell it.
Who is responsible
These websites are run by me, Sanjib Sikder, an independent teacher in Kolkata, India. This policy covers sanjibsikder.com and all its sub-sites, including the Academy and the practice site.
Contact for anything about your data: sanjibju2002@gmail.com or WhatsApp +91 70445 58001.
This homepage
- No accounts, no cookies, no advertising trackers.
- The enquiry form does not send anything to my server. It only prepares a WhatsApp message on your device. Nothing reaches me until you press Send in WhatsApp, and then it is an ordinary WhatsApp message, handled under WhatsApp's own privacy policy.
- While you fill in the form, your answers are kept on your own device (in the browser's local storage), so they are still there if you come back. Your choice of light or dark theme is stored the same way. You can clear both by clearing this site's data in your browser.
- Like almost every web server, mine keeps short technical logs (IP address, browser type, the page requested, time) for security and to fix faults. They are not used to identify or profile visitors.
Visit counts
On some of my sites I count visits (for example, which pages are read and how often) to learn what is useful. This is done with my own tools and my own database, not with advertising networks, and it is not used to identify individual visitors or to show anyone advertising.
The learning platform (for enrolled students)
Students sign in with their Google account. When they do, I receive from Google only their name, e-mail address and profile picture. I do not get their Google password or access to their Gmail, Drive or anything else.
While a student studies, the platform stores what it needs to teach: answers to practice problems and tests, marks, mistakes and when they come back for revision, daily practice and formula sessions, and progress through the book.
I use this to:
- plan classes and choose the right problems for each student;
- share test marks with the student's parents;
- keep the platform working and secure.
A single sign-in cookie keeps the student logged in across my sites. It is needed for the platform to work. There are no advertising cookies.
Children
Most of my students are under 18. A student under 18 is enrolled by a parent or guardian, who agrees to this policy on the student's behalf. Parents may ask what is stored about their child, and may ask me to correct or delete it. I do not show advertising to students and do not track them for advertising.
Who else handles the data
I do not sell or rent personal data, and I do not share it with anyone for marketing. It is handled only by the services needed to run the platform:
- A hosting provider: the rented server that runs the websites and the database;
- Google: sign-in, and storage of the daily backups (Google Drive);
- WhatsApp: only for messages you choose to send me.
Students' personal data is not sent to AI services. I may disclose information if the law requires it.
How long it is kept
I keep a student's data while they study with me and afterwards, so that past results stay available. If you ask, I delete it, except records the law requires me to keep (for example, fee records). Deleted data can remain in older backups for a while; backups are used only to recover from a fault.
Your rights
You may ask for a copy of the data held about you or your child, or ask me to correct or delete it; you can also withdraw consent by asking me to close the account. Write to sanjibju2002@gmail.com or message me on WhatsApp. I will reply within 7 days.
Changes
If this policy changes, the new version will be posted on this page with a new date.