NewQuetext is now on Firefox

Check plagiarism and AI content without leaving Firefox.

Highlight text on any page, run a scan, and get instant results without switching tabs. The same DeepSearch™ engine trusted by over 10 million students, teachers, and professionals is now in your Firefox toolbar.

Add to Firefox, it’s free

Using Chrome? Get the Chrome extension →

Free plan: up to 1,000 words
Plagiarism + AI detection in one scan
Official Firefox Add-ons listing

Quetext report opened from the Firefox toolbar, showing plagiarism matches, an AI score and sources side by side

Get started in under a minute

How to install the Quetext Firefox extension

01
Open the Firefox Add-ons page
Go to the Quetext listing on addons.mozilla.org and click Add to Firefox.
02
Approve and pin it
Confirm the permissions prompt, then pin Quetext to your toolbar from the Extensions menu.
03
Log in or sign up
Use your existing Quetext account, or create a free one in seconds.
04
Highlight any text
Select a paragraph on any webpage, such as a blog post, a student submission or client copy.
05
Run the scan
Click the Quetext icon and choose Check Plagiarism or check for AI content.
06
Review and fix
See flagged passages color-coded with sources side by side, and fix them right away.

Everything from Quetext, in your toolbar

Verify content without interrupting your workflow

Same engine, same database, same accuracy as the full Quetext platform. The only difference is where you start the scan.

DeepSearch™ plagiarism detection

Catches exact copies and cleverly reworded text with Contextual Analysis, Fuzzy Matching and Conditional Scoring.

AI content detection

Identify text from ChatGPT, Gemini and other LLMs with a clear AI Score, flagged alongside plagiarism results.

ColorGrade™ feedback

Exact matches, near matches, paraphrased content and AI-flagged sections, each clearly marked with sources side by side.

Grammar & citations

Grammar checking in 6 dialects of English and 9 more languages, plus MLA, APA and Chicago citations.

Under the hood

How DeepSearch™ works in Firefox

Every scan you run in Firefox goes through the same three-step process that powers Quetext’s full plagiarism checker and AI Content Detector

Explore our technology →

Contextual Analysis
Looks beyond individual words to the context of phrases, catching plagiarism even when wording has been rearranged or lightly edited.
Fuzzy Matching
Flags synonym swaps, sentence restructuring and patchwork plagiarism that simpler tools miss.
Conditional Scoring
Weights each flagged passage against your overall score for a nuanced percentage, not a simple pass/fail.

Who is the Firefox extension for?

Students

Check your sources, keep the work original and generate citations when needed.

Teachers & professors

Review student work and spot plagiarism and AI use in assignments.

Copywriters & marketers

Audit your content and verify submissions before they go to clients.

Bloggers & SEOs

Avoid duplicate content and check competitor pages to keep up with best SEO practices.

Researchers

Validate your research sources and scan academic material before publishing.

One account. Your browser of choice.

Firefox New

Plagiarism and AI checks from the Firefox toolbar. Available on Firefox Add-ons.

Add to Firefox

Chrome

The original Quetext extension, available on the Chrome Web Store.

Get the Chrome extension

Microsoft Edge

Plagiarism and AI checks from the Edge toolbar. Available on Microsoft Edge Add-ons.

Get the Edge extension

Any browser

Use the full Quetext plagiarism checker and AI detector on the web, anywhere.

Open Quetext

Firefox extension FAQ

How do I check for plagiarism in Firefox?

Install the Quetext add-on from Firefox Add-ons, highlight text on any webpage, click the Quetext icon in your toolbar and choose Check Plagiarism. You get a color-coded report in seconds. You can also upload .doc, .docx, .pdf or .txt files.

How do I install the Quetext Firefox extension?

Open the Quetext listing on addons.mozilla.org and click Add to Firefox. Approve the permissions prompt, pin Quetext to your toolbar from the Extensions menu, then log in or create a free account.

Is the Quetext Firefox extension free?

Yes. The add-on is free to install, and the free plan lets you check up to 1,000 words per feature. Paid plans unlock higher limits, bulk uploads, grammar checking and downloadable reports.

Can I detect AI-generated content in Firefox?

Yes. The extension runs Quetext’s AI detector alongside the plagiarism check. You get an AI Score and flagged sections for text that looks like it came from ChatGPT, Gemini or other AI models.

Is the Firefox extension the same as the Chrome extension?

Yes. Both use the same DeepSearch™ engine, AI detector and database, and you sign in with the same Quetext account. Your plan and reports work in both browsers.

Do I need a Quetext account to use the Firefox extension?

Yes. An account keeps your reports secure and lets you track them. Log in with your existing details or create a free account in seconds.

What if I need to check more than 1,000 words?

Upgrade to a paid plan. Paid plans support much longer checks plus bulk uploads, source exclusion and enhanced reports.

Does the Firefox extension work on Google Docs?

It works on most pages with selectable text, including many online editors. In Google Docs, select the section you want to check for the best results.

Which languages does the Firefox extension support?

English (US, UK, Australia, Canada, New Zealand, South Africa) plus French, Spanish, German, Italian, Portuguese, Polish, Romanian, Dutch, Turkish, Vietnamese and Indonesian.

How accurate is the Firefox extension compared with quetext.com?

It is just as accurate. It uses the same DeepSearch™ technology (Contextual Analysis, Fuzzy Matching and Conditional Scoring) and scans billions of web pages, over 20 million books and more than 1 million academic journals. Only the way you submit text changes.

Can I generate citations from the Firefox extension?

Yes. Use the built-in citation tool to create MLA, APA or Chicago citations for flagged passages without switching tools.

Can I check multiple documents at once?

Yes, on paid plans. Bulk upload lets you scan up to 100 documents at a time.

Is Quetext available in other browsers?

Yes. Quetext has extensions for Chrome and Firefox, and the full plagiarism checker and AI detector work in any browser at quetext.com. You can also connect through Quetext MCP or the Quetext API.

Write with confidence, right in Firefox.

Install free in seconds. Upgrade anytime for higher limits and access to all features.

Add to Firefox See pricing