Privacy
Privacy policy
Last updated 8 November 2026
We collect what we need to run MathLens and nothing else. We don't sell your data and we don't show ads.
What we collect
- Your account. Your email address and, if you give it, your name. If you sign up with email, your password is stored only as a scrambled one-way hash. If you sign in with Google, we receive your Google account ID, email address and name from Google.
- Your lessons. The questions you ask and the lessons the tutor writes, so they can be saved in your notebook.
- Documents you upload. Your browser reads the text out of the file; the file itself never leaves your device. The text is sent along with your question to write the lesson. We keep the lesson and a short fingerprint of the text (so we can recognise the same document again), not the text itself.
- Payments. The amount and Razorpay's order and payment IDs. Your card, UPI and bank details go straight to Razorpay; we never see them.
- Usage. For each lesson, how much it cost to make, and the IP address it came from. We use the IP address to stop people collecting free lessons unfairly.
- Cookies and browser storage. A cookie that keeps you logged in, and a cookie that counts free tries before you sign up. Your browser also remembers your light or dark theme and which lessons you've opened. We don't use advertising or tracking cookies.
Who else sees it
- OpenAI, the company whose AI model writes the lessons, receives your question and any document text in order to write the lesson.
- Razorpay processes payments.
- Google, if you choose to sign in with Google.
- Our email provider receives your email address if you ask for a password reset link.
- The pages load fonts from Google Fonts and code libraries from jsDelivr. Like any website you visit, they can see your IP address.
How long we keep it
Your account and saved lessons stay until you delete them. You can delete any lesson from your notebook yourself. Payment records are kept for as long as the law requires.
Your choices
To get a copy of your data or to delete your account, email [email protected] from the address on your account.
Young learners
If you're under 18, please use MathLens with a parent's or guardian's permission.
Keeping it safe
Passwords are hashed, login cookies can't be read by scripts on the page, and the site is served over an encrypted connection.
Changes
If we change what we collect or who we share it with, we'll update this page and the date at the top.