Chrome extension · v0.6.11

Your tutor, on the page you're already reading.

Highlight a passage and ask about it in a side panel, without losing your place. It uses the CANtutor account you already have.

Download for Chrome Installation instructions

Direct download · unzip and load in Chrome. Follow the installation instructions below.

Included with every CANtutor plan. Needs Chrome 116 or newer on a computer.

See how it works

your-school.example/biology/unit-3/enzymes

Unit 3 · Reading

How enzymes work

Every reaction in a cell needs a push to get started. Enzymes lower the activation energy of a reaction. The substrate binds at the active site, forming an enzyme–substrate complex, and the enzyme is released unchanged. Temperature and pH change the shape of the active site.

CANtutorNew chat

Highlighted text

Enzymes lower the activation energy of a reaction. The substrate binds at the active site, forming an enzyme–substrate complex, and the enzyme is released unchanged.

Why is the enzyme unchanged?

It only holds the substrate in place while the reaction happens. None of its own bonds are used up, so it can:

bind the next substrate
run the same reaction again

Copy

Ask a follow-up

Illustration of the extension, not a screenshot.

Install in Chrome

This release is a direct download. Use Chrome 116 or newer on a computer.

Download the zip above and unzip it into a folder you can keep.
Open chrome://extensions in Chrome's address bar.
Turn on Developer mode, then choose Load unpacked.
Select the unzipped folder containing manifest.json. Keep that folder in place while you use the extension.
Sign in at cantutor.ai, then pin CANtutor from Chrome's Extensions menu and open its panel.

If your school manages Chrome and blocks Developer mode, ask your school's administrator about installation.

How it works

Highlight. Ask. Keep reading.

01
Read the way you already do.
Your course page, an article, a Google Doc. The extension waits in Chrome's toolbar until you need it.
02
Highlight, then ask.
Select a passage and an Ask CANtutor button appears beside it. On sites where it doesn't, right-click the selection instead.
03
Get an answer beside the page.
A side panel opens next to what you're reading, not over it. Ask a follow-up and it remembers the thread.
your-school.example/biology/unit-3/enzymes
Unit 3 · Reading
How enzymes work
Every reaction in a cell needs a push to get started. Enzymes lower the activation energy of a reaction. The substrate binds at the active site, forming an enzyme–substrate complex, and the enzyme is released unchanged. Temperature and pH change the shape of the active site.
CANtutorNew chat
Highlighted text
Enzymes lower the activation energy of a reaction. The substrate binds at the active site, forming an enzyme–substrate complex, and the enzyme is released unchanged.
Why is the enzyme unchanged?
It only holds the substrate in place while the reaction happens. None of its own bonds are used up, so it can:
bind the next substrate
run the same reaction again
Copy
Ask a follow-up
04
Turn the page into a Study Pack.
Notes, flashcards and a quiz from what you're reading, saved to your CANtutor account so you can open them anywhere.
your-school.example/biology/unit-3/enzymes
Unit 3 · Reading
How enzymes work
Every reaction in a cell needs a push to get started. Enzymes lower the activation energy of a reaction. The substrate binds at the active site, forming an enzyme–substrate complex, and the enzyme is released unchanged. Temperature and pH change the shape of the active site.
CANtutorNew chat
Study Pack
From: How enzymes work
NotesKey ideas from the page
FlashcardsTerms and definitions
QuizCheck yourself
Saved to your CANtutor account
05
Show it what isn't text.
For a diagram or a PDF in Chrome's viewer, send one still picture of your screen. Chrome asks what to share first.
One picture, then it stops. It is not a screen share.
your-school.example/biology/unit-3/enzymes
Unit 3 · Reading
How enzymes work
Every reaction in a cell needs a push to get started. Enzymes lower the activation energy of a reaction. The substrate binds at the active site, forming an enzyme–substrate complex, and the enzyme is released unchanged. Temperature and pH change the shape of the active site.
CANtutorNew chat
Show it my screen
This picture goes with your next question.
One still picture, then it stops. It is not a screen share.

your-school.example/biology/unit-3/enzymes

Unit 3 · Reading

How enzymes work

your-school.example/biology/unit-3/enzymes

Unit 3 · Reading

How enzymes work

Ask CANtutor

your-school.example/biology/unit-3/enzymes

Unit 3 · Reading

How enzymes work

CANtutorNew chat

Highlighted text

Enzymes lower the activation energy of a reaction. The substrate binds at the active site, forming an enzyme–substrate complex, and the enzyme is released unchanged.

Why is the enzyme unchanged?

It only holds the substrate in place while the reaction happens. None of its own bonds are used up, so it can:

bind the next substrate
run the same reaction again

Copy

Ask a follow-up

your-school.example/biology/unit-3/enzymes

Unit 3 · Reading

How enzymes work

CANtutorNew chat

Study Pack

From: How enzymes work

NotesKey ideas from the page

FlashcardsTerms and definitions

QuizCheck yourself

Saved to your CANtutor account

your-school.example/biology/unit-3/enzymes

Unit 3 · Reading

How enzymes work

CANtutorNew chat

Show it my screen

This picture goes with your next question.

One still picture, then it stops. It is not a screen share.

Illustration of the extension, not a screenshot.

Highlight anything, ask about it

Select text on Canvas, Khan Academy, YouTube or a Google Doc and an “Ask CANtutor” button appears beside it. Anywhere else, right-click your selection, or turn the button on for that one site from the panel.

Or take the whole page

Nothing highlighted? “Use this whole page” pulls the readable text off the page in front of you (no navigation, no cookie banners) and hands it to the tutor.

It's a conversation, not one question

Ask a follow-up and the tutor remembers what you just asked. The panel keeps the thread, formats the answer properly (headings, lists, bold, code), and every reply has a copy button. “New chat” ends it on our side too, not just on your screen.

Turn it into a Study Pack

Notes, flashcards and a quiz from whatever you are reading, built in the panel and saved to your CANtutor account, where you can open them again from any device.

Let it see your screen

For a PDF in Chrome's viewer, a diagram, or maths a page draws as a picture: anything there is no text to read. Chrome asks you to pick a screen, a window or a tab, and only that is sent. One picture, then it stops; it is not a screen share.

Read a Google Doc properly

Docs draws its text onto a canvas, so no extension can read it off the page. CANtutor pulls the document itself with your own Google session, and asks permission first, for Google Docs only.

There's a keyboard shortcut. Alt + Shift + C opens the panel and brings your selection with it. You can change it in Chrome's keyboard shortcut settings.

What it can't do

Before you install it, not after.

PDFs in Chrome's own viewer can't be read

Chrome's PDF viewer is itself an extension drawing into a plugin frame, and no other extension can see inside it. The panel says so and gives you a box to paste into instead.

Chrome only

The side panel API this is built on is Chrome's. Firefox and Safari have different ones with different lifecycles, so this build does not run there.

Self-hosted Canvas needs one click

Canvas runs on thousands of university domains and no extension can list them all. Right-click works there immediately; “Show the highlight button on this site” in the panel makes it permanent for your school's domain.

It needs a CANtutor session

Sign in at cantutor.ai once, in a normal tab. The extension has no account of its own, so signing out of the site signs the extension out in the same instant.

What leaves your browser

Only what you send: the passage you highlighted, the page title and address, and your question. No analytics, no third-party script, no telemetry. Highlights live in memory and die with the tab. Read the extension's privacy policy.

Add it to Chrome.

It rides your normal cantutor.ai session: no second login, no key to paste. No account yet? Start there first.

Download for Chrome Installation instructions

Direct download · unzip and load in Chrome. Follow the installation instructions below.

Try now

Your tutor, on the page you're already reading.

Install in Chrome

Highlight. Ask. Keep reading.

Read the way you already do.

Highlight, then ask.

Get an answer beside the page.

Turn the page into a Study Pack.

Show it what isn't text.

What it can't do

Add it to Chrome.