Before you use this, here is everything the extension handles — there is nothing else, and none of it happens until you ask for it.
Text you highlight, and the page's title and address
Sent only when you press Ask CANtutor, use the right-click item, or build a Study Pack. A selection you never act on is never read.
One still picture of your screen, if you ask for it
Only after you press Show it my screen and choose a screen, window or tab in Chrome's own picker. One frame is taken and the capture stops immediately — no recording, and never any audio. The picture is whatever you pointed at, so close anything you would rather not send.
A Google Doc, only the one you ask it to read
Only if you grant the Google Docs permission and press the button, and only using the Google session already in your browser.
All of it goes to cantutor.ai, signed in as you, and on to OpenAI, the AI provider that writes the answer, which acts as a processor for us and is contractually barred from training its own models on your work. Nothing is sold, rented or shared for advertising, there is no analytics or tracking, and the extension stores nothing on disk except your Learn/Practice/Answer choice and this agreement.
Ask about something you highlighted
Select text on any page. On Canvas, Khan Academy, YouTube and Google Docs an Ask CANtutor button appears next to it. Anywhere else, right-click the selection and choose Ask CANtutor about "…", or press the keyboard shortcut.
Ask about the whole page
Nothing highlighted? Use this whole page takes the readable text off the page in front of you — the lesson, not the menus, cookie banners or comments. Equations come through as maths rather than being dropped.
Let it see your screen
Show it my screen sends a picture of what you're looking at. Chrome asks you to pick — a whole screen, one window, or one tab — and only that is sent. Use it for a PDF in Chrome's viewer, a diagram, a graph, a second monitor, or a hand-written page: anything there is no text to read. One picture, then it stops; this is not a screen share.
Turn it into a Study Pack
Notes, flashcards and a quiz from whatever you're reading. Needs about a paragraph to work with. Packs are saved to your CANtutor account — .
Keep asking, and find it later
Follow-ups continue the same conversation, so you can say "why?" and it knows what you mean. New chat starts over, and answers have a Copy button.
Everything you ask here is saved to your CANtutor account and shows up under on the web, on iPhone and on Android.
Three ways to be taught
Learn explains it. Practice makes you try first. Answer just tells you. Switch at the top; it remembers.
Shortcut
Alt+Shift+C opens this panel on
whatever you're reading and brings your selection with it. Change it
at chrome://extensions/shortcuts.
What it can't do
It can't read the text inside Chrome's PDF viewer, and it can't read maths that a page draws as a picture — use Show it my screen or paste instead. On your school's own Canvas domain the highlight button needs turning on once, at the bottom of this panel.
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Checking your CANtutor session…
This extension uses your normal cantutor.ai session — there's no separate account and no password to give it. Sign in once in a tab and come back.
Highlight something to get started.
Select text on the page and press the Ask CANtutor button, or right-click your selection and choose Ask CANtutor about "…".
Nothing highlighted? Ask about everything on the page instead.
Reading a PDF in Chrome's own viewer? Chrome doesn't let extensions see the text in it — copy the part you want and paste it below.
This looks like a Google Doc. Chrome can't read the text off the page — Docs draws it onto a canvas — but CANtutor can pull the whole document with your own Google session.
This picture goes with your next question.