Does Canvas Detect Chrome Extensions? What a Web Page Can See

Canvas itself has no documented feature that shows instructors a list of your Chrome extensions, and Chrome does not give websites a way to ask for that list. That is not the same as "Canvas can't notice extensions". Any web page, Canvas included, can observe changes an extension makes to the page, probe for certain known extensions, and watch focus, copy and paste events. Proctoring tools used with Canvas, such as Proctorio and Honorlock, are Chrome extensions themselves and can see far more; Respondus LockDown Browser replaces Chrome entirely. Here is what each layer can actually do, based on Google's and the vendors' documentation.

Last verified: October 12, 2026 against the official documentation linked below.

Three different questions hiding in one

"Does Canvas detect Chrome extensions?" usually means one of three things, and the answers are different:

1. Does Canvas show my instructor which extensions I have installed? Not as a documented feature. Instructure's instructor guides for the quiz log, the Moderate page, the Access Report and Course Analytics do not include any extension list.
2. Could a web page like a Canvas quiz notice that an extension is active? Sometimes, yes. Browsers isolate extensions, but not completely, as explained below.
3. Can a proctoring tool used in my Canvas course see or block extensions? Yes. Several are designed to do exactly that.

If your real question is what your instructor sees in general, start with our guide to the Canvas quiz log. If it is about people rather than software (professors, school IT, a school Chromebook), see can professors see your Chrome extensions?

What browser sandboxing really protects

Chrome isolates extensions from the pages they run on in a few specific ways. Google's content scripts documentation says content scripts "live in an isolated world", a private execution environment that is not accessible to the page, and that "JavaScript variables in an extension's content scripts are not visible to the host page". There is also no web API that returns the list of installed extensions to a normal website.

But the same page states the important exception: content scripts and the host page "share access to the page's DOM". Anything an extension adds to or changes in the page (a button, a panel, a highlight, a modified attribute) is part of the same document the page's own code can read. And extensions can choose to run scripts in the page's main world rather than the isolated one, which removes even the variable isolation. Sandboxing protects the extension's private data; it does not hide the extension's effects.

What a web page can observe about extensions

These are the techniques available to any website. Whether Canvas or a given quiz tool uses them is a separate question (Instructure does not document doing so), but the claim that "Chrome closed every way to see extensions" is simply false.

A few of these deserve detail.

Web-accessible resources. Google's manifest documentation says that "by default no resources are web accessible, as this allows a malicious website to fingerprint extensions that a user has installed". In other words, Google itself acknowledges that a page can identify an extension through any file the extension chooses to expose. The use_dynamic_url option, which regenerates the URL when the browser restarts, exists to reduce exactly that.

Copy and paste. MDN notes that a paste handler "can access the clipboard contents by calling getData()" (MDN: paste event). A page can therefore know that text was pasted into an answer box and what it was. For reference, the Classic Quizzes log trackers in the canvas-lms source code cover session start, questions viewed, page blur/focus and flagged questions; none of them records clipboard events. That describes today's Classic log, not what every quiz tool or future version might do.

Focus. Opening an extension's toolbar popup or clicking into a side panel generally takes focus away from the page, which is the same event Canvas logs as "Stopped viewing the Canvas quiz-taking page". Our article on Canvas tab-switch tracking explains that event in detail.

What proctoring tools used with Canvas can do

This is where "can Canvas see my extensions?" gets a much clearer yes. Proctoring products integrate with Canvas quizzes and run with far more access than a web page.

Proctorio

Proctorio is a Chrome extension. Instructors choose lock-down options per quiz, and one of them is Disable Extensions. The University of Tennessee at Chattanooga's Proctorio guidance tells instructors the option "should be used on EVERY quiz using Proctorio", and McGraw Hill's support site documents an error caused by "the 'Disable Extensions' setting" (McGraw Hill support). Chrome provides an API for this: the chrome.management API lets an extension with the "management" permission list installed extensions (getAll) and turn them on or off (setEnabled). An extension, unlike a web page, can see your extension list.

Honorlock

Honorlock also runs as a Chrome extension. Its test-taker privacy statement says it can log "the websites you attempt to visit through Chrome while you are taking the exam" and, when your school enables it, record you through your webcam and capture your desktop activity. It also says some organizations require additional software alongside the extension "to detect prohibited programs". A desktop recording shows whatever an extension displays on screen.

Respondus LockDown Browser

Respondus LockDown Browser is "a custom browser that locks down the testing environment". Students cannot access other applications or websites, copying and pasting is prevented, and quizzes set up for it "cannot be accessed with other browsers" (Respondus). Because the quiz runs outside Chrome, your Chrome extensions are not present at all. Instructure's Classic Quizzes options guide notes that LockDown Browser appears under Quiz Restrictions when the institution has enabled the integration.

Canvas alone vs Canvas with proctoring

A concrete example: how a page could notice a helper extension

To make this less abstract, imagine an extension that adds a small button next to every quiz question. Here is what is technically available to the quiz page, step by step, without any special permission:

1. The page registers a MutationObserver, a standard browser API that reports every element added to, removed from or changed in the document. When the extension inserts its button, the observer is notified with the new element, its tag, its classes and its position.
2. The page compares what it sees with what it rendered. A quiz application knows exactly which elements it created; anything else inside the question area is, by definition, added by something else: an extension, a translation tool, a grammar checker or an accessibility tool.
3. If the extension exposes a web-accessible file at a fixed address, the page can also request that address and see whether it loads, which identifies the extension by its ID.
4. If the user opens the extension's popup, the page receives a blur event, and the quiz log on Canvas records "Stopped viewing the Canvas quiz-taking page".

None of this tells the page what the extension said to the student, and a page has to be written to look for these signals in the first place. Instructure does not document that Canvas quizzes do this. But it shows why "websites can't see extensions" is an oversimplification: a page cannot read your extension list, yet it can often see an extension's footprint. Grammar checkers are the everyday example: they visibly add elements next to text fields on many sites.

What instructors rely on instead of software detection

In practice, most instructors never think about extensions at all. They design quizzes and read results in ways that make outside help less useful or more visible, using settings Canvas documents:

• Quiz design. New Quizzes settings include shuffled questions and answers, one question at a time with or without backtracking, time limits, an access code, IP filtering and Detect Multiple Sessions (Instructure: New Quizzes settings). Question banks and randomized groups mean two students rarely see the same quiz.
• Statistics. Classic Quizzes statistics show the average, high and low scores, standard deviation and per-question breakdowns, and a Student Analysis CSV lists each response (Instructure: quiz statistics). Outliers in time or score stand out without any extension detection.
• The quiz log. Timestamps of each answer and each focus change give a timeline of the attempt.
• Assessment format. Many courses have moved weight to in-class exams, oral follow-ups, handwritten work or projects, precisely because no web page can fully control what happens around a student's computer.

For the full settings list, see Canvas quiz settings explained.

The other direction: what extensions can see about you

One point students rarely consider: the sandbox is asymmetric. A website sees little about your extensions, but an extension with permission to run on all sites can read every page you open in Canvas, including grades, messages and submissions. Chrome shows a permission warning when you install such an extension. Before installing any study tool, check who publishes it, what it asks for, and its privacy policy, and remove extensions you no longer use. That applies to QuizAce as much as to any other extension.

Common myths, corrected

• "Chrome closed all extension-detection loopholes." False. Google's own documentation describes fingerprinting through web-accessible resources, and any extension that changes the page leaves traces in the shared DOM.
• "The user agent reveals your extensions." Also false. The user agent string that Canvas records at quiz start identifies the browser and operating system, not extensions.
• "If Canvas doesn't list extensions, using one is fine." Whether a tool is allowed is a rule set by your instructor and institution, not a technical question. Many syllabi and academic-integrity policies address AI tools explicitly, and an instructor can act on timing, answer patterns or a proctoring recording regardless of how the tool was or was not noticed.
• "Proctoring only watches the webcam." Depending on settings, it can also control tabs, the clipboard, extensions and screen recording.

What to do before a graded Canvas quiz

• Read the quiz instructions and your syllabus for rules about outside resources and AI tools. If they are unclear, ask your instructor.
• If the quiz uses Proctorio, Honorlock or LockDown Browser, expect extensions to be disabled, restricted or recorded. Some extensions can even stop a proctored session from starting, so check the proctoring tool's system check ahead of time.
• Treat practice quizzes and homework as the place to use study tools. Our guide on studying with AI tools covers how to use them to learn rather than to shortcut.

Sources

• Chrome for Developers: Content scripts (isolated worlds, shared DOM)
• Chrome for Developers: web_accessible_resources (fingerprinting, use_dynamic_url)
• Chrome for Developers: chrome.management API
• MDN: MutationObserver
• Instructure: How do I manage settings for a quiz in New Quizzes?
• Instructure: What kinds of quiz statistics are available?
• MDN: Element paste event
• canvas-lms source code: quiz log event trackers
• Instructure: What options can I set in a quiz?
• Respondus: LockDown Browser
• Honorlock: Test taker privacy statement
• University of Tennessee at Chattanooga: Proctorio best practices
• McGraw Hill support: Proctorio "Disable Extensions" error

FAQ

Can Canvas see what extensions I have?

Canvas has no documented feature that shows instructors your extension list, and websites cannot request that list from Chrome. A page can still notice some extensions through changes they make to the page or files they expose, and proctoring extensions can read the list directly.

Can Canvas detect AI extensions during a quiz?

There is no Canvas setting labelled that way. What exists is the quiz log (focus changes, answers, timing), the general ability of a page to observe DOM changes, and proctoring tools that can disable or record extensions. Instructors also review answer patterns and timing.

Does Proctorio disable Chrome extensions?

It can. Disable Extensions is one of Proctorio's lock-down options, chosen by the instructor for each quiz, and university guidance recommends it for every Proctorio quiz.

Do Chrome extensions work in Respondus LockDown Browser?

No. LockDown Browser is a separate browser, so your Chrome extensions are not loaded, and quizzes set up for it cannot be opened in Chrome.

Can Canvas see my other tabs?

No. The quiz log records that the quiz page lost focus and when, not which tab or site you went to. Proctoring tools such as Honorlock can log visited websites when enabled.