Privacy Policy

Last updated September 15, 2026

This page explains what Lemmaris collects when you use it, why, and what you can do about it. The short version: we keep what is needed to run your account and save your learning, we do not sell it, and we do not use ads or tracking cookies.

What we collect

• Your account. Your email address, your display name, and your password stored as a salted one-way hash. We cannot see your password. If you sign in with Google, we store the account identifier Google gives us and the email Google confirms.
• Your learning. Lessons started and finished, answers you give inside a lesson, XP, streaks, quests, gems, and where you left off in a lesson, so you can resume it on another device.
• How the product is used. A short record of things like starting or finishing a lesson, keeping a streak, passing a quiz, or getting a reminder email, with the time and details such as the lesson or streak length. We keep this in our own database to see what helps people keep learning and to compare two versions of a feature. It is never sent to an analytics company.
• Security records. When you log in, we keep a record of the session so we can end it when you log out. To slow down password guessing, we count recent attempts using scrambled (hashed) versions of the email address and network address involved.

What happens when you ask Chip a question

When you type a question to Chip, the text of your question and the lesson you are in are sent to an AI model provider (currently OpenAI) to write his reply. Your name, email and account are not sent with it. If you use the microphone, your browser turns speech into text, and your browser maker may process that audio under its own policy. Chip's voice is produced by your own browser.

Course contributions

Course materials are extracted in your browser. When you save them, we store the extracted text privately under your account, not the original file. Topic processing may send this text to the configured AI provider. Remove personal information before saving. Sharing is a separate choice: accepted topic names become public and selected short evidence excerpts are available to signed-in contributors for review. Withdrawing material or deleting your account removes its text and shared excerpts. Course pages, topic names, roadmap versions and review notes can remain as shared history, without your account identity. Do not put private information in those shared fields.

My Notes

Notes you add to My Notes are stored privately under your account and are never published, shared or used to build courses. Files are read in your browser; we keep the extracted text, and a photo is kept as an image only you can view. When you press Study this, the text of the notes you picked (never images) is sent to the configured AI provider (currently OpenAI) to build your study session. Your name and email are not sent with it. Deleting a note deletes its text, its image and every study session built from it; deleting your account deletes all of them.

Cookies and storage

• lemmaris_session keeps you logged in, for up to 30 days.
• volt_learner saves your progress while you learn as a guest, for up to a year.
• lemmaris_oauth exists for up to ten minutes while you sign in with Google.
• Your browser's local storage remembers small choices, such as dismissing a reminder.

All of these are needed for the site to work. There are no advertising or analytics cookies.

Who else handles your data

Lemmaris runs on Cloudflare, which hosts the site and its database and sends our emails. OpenAI processes questions you ask Chip and the notes you choose to study, as described above. Google is involved only if you choose to sign in with Google. We do not sell your information or share it for advertising.

Leaderboards

When you earn XP in a week, you join a weekly league with up to nine other learners in the same course. They see the first word of your display name and your XP for that week, and nothing else: not your email, your full name, or your answers. Seats nobody has taken are filled with simulated rivals, labeled on the row. You can hide yourself from leaderboards in Settings.

Reminder emails

If your email is confirmed and you have a streak, Chip may send one reminder on a day you have not practiced yet, never more than one a day. Every reminder has a one-click unsubscribe link, and you can turn reminders off in Settings.

How long we keep it

We keep your account and progress until you delete your account. Deleting it from Settings removes your account, your sessions and your learning progress straight away, and takes you off leaderboards at once. Your reminder setting and usage records are removed within a day. Guest progress is kept so you can return to it; write to us if you want it removed.

Your choices

• Change your name, email and password in Settings.
• Log out of every device at once in Settings.
• Turn off reminder emails, or hide yourself from leaderboards, in Settings.
• Delete your account and progress in Settings.
• Ask us for a copy of your data, or anything else about your privacy, at support@lemmaris.com.

Children

Lemmaris is built for college students and is not directed at children under 13. We do not knowingly collect information from them.

Changes

If we change what we collect or how we use it, we will update this page and the date at the top.