The GPTZero free plan: characters, words and your text

What the pricing page says about the free plan

GPTZero’s pricing page, read in a browser on 6 November 2026, sets out three plans. The Free plan costs 0 EUR and lists up to 10,000 words per month, a Basic AI Scan, 1 Free Advanced Scan and five free AI highlights in the Chrome Extension. The text we downloaded from the page did not show the plan cards, so these figures come from the page as a browser displays it. The prices appeared in euros for the browser we used, and we report them in euros, written as the page wrote them, with a comma before the cents.

Premium is 9,99 EUR a month billed annually, with up to 300,000 words per month, an Advanced AI Scan, Multilingual AI detection, reports to download and AI highlights in the Chrome Extension. Professional is 19,99 EUR a month billed annually, with up to 500,000 words per month, everything in Premium, an overage of up to 2 million words, page by page scanning and an LMS integration with enterprise grade security. It also lists “Scan up to 250 files at once”. A switch at the top of the page offers Annual, marked Save 45%, or Monthly. We read the annual view, so the monthly prices are not in this page.

The same page describes a Team plan. Every seat gets the Professional plan with shared team credits, unified billing and seat management, and up to 500,000 words per member, per month. The minimum is 2 seats, payment is by card only, and the page sends purchase orders, invoicing and larger teams to sales. We did not read a price for the Team plan.

One detail of the Free plan is left open. The page says 1 Free Advanced Scan and does not say whether that is one a month or one in all. The pages we read do not explain it.

Two limits: characters for a scan, words for a month

The home page of GPTZero shows a scan box with a counter that reads 0 / 10,000 characters, followed by the word Upgrade. Its first step says to paste text or upload a document, and that for scans over 10,000 characters you should create a free account first. So 10,000 characters is the size of a scan before an account is opened.

The monthly figure is in words. The pricing page lists up to 10,000 words per month for Free, and the students page answers its own question about the best free detector by saying GPTZero offers a free plan built for education, with up to 10,000 words a month and the Chrome Extension. Wikipedia puts both limits in one sentence: as of September 2025, free tier users can scan up to 10,000 words a month, with a maximum of 10,000 characters per scan. Read together, they describe one plan with two limits, one for each scan and one for each month.

Characters and words are two different measures, and the pages we read use each one for a different limit.

The FAQ adds a third figure. To get the detector for texts up to 150,000 characters, or a batch of up to 250 files, it says to sign up for a free account. The pricing page, on the other hand, puts “Scan up to 250 files at once” under Professional. The pages we read do not say how the two fit. They also do not say how the scan limit and the monthly allowance combine, or what happens when the allowance is used.

The Chrome Extension and what the free plan lists

The Chrome Extension page says the extension is free to install and use with a GPTZero account, including “a monthly allowance” of AI detection scans, highlighting sessions and chat messages, and that paid plans raise those limits. That page gives no number. The pricing page does give one, for the Free plan: five free AI highlights in the extension, while its Premium plan lists AI highlights with no number. The two pages use different wording, and the pages we read do not say whether they describe the same allowance.

The extension page lists what the extension does: it scans any webpage, runs automatic scans and sentence-level AI highlighting in Google Docs, shows AI labels on a Gmail inbox, replays a document’s writing history, grades papers against a rubric and offers a chat with an AI writing assistant beside the document. It calls all of this one free extension. Which of these uses count against the monthly allowance is not written on that page.

On what a scan returns, the FAQ says GPTZero shows where AI is used at document, sentence and word level, and that it gives confidence scores. The home page presents Advanced Scan and Writing Replay as separate parts of its toolkit, and a section called Premium Features lists video proof of the writing process, Advanced Insights, a plagiarism detector and “Free grammar check and feedback”. The Free list on the pricing page names a Basic AI Scan and 1 Free Advanced Scan; it does not mention Writing Replay or the plagiarism detector.

The free plan in 2023 and in 2026

A TechRepublic guide dated 27 March 2023 describes a different set of plans. The free one, GPTZero Classic, limited a document to 5,000 characters and an upload to three files. Educator cost $9.99 a month, allowed 50,000 characters per document and analysed up to 1 million words per month. Pro cost $19.99 a month, allowed 50,000 characters per document and analysed up to 2 million words per month, with an API Beta trial.

Set beside the pricing page of November 2026, two things have changed. The names are different: Classic, Educator and Pro are not the names on the 2026 pricing page, which lists Free, Premium and Professional (the pages we read do not say which plan replaced which). And the free limit is counted differently: the 2023 guide counts characters per document and files per upload, while the 2026 pages count words per month and characters per scan. The prices are in dollars in one and euros in the other, so we do not set them side by side as a rise or a fall.

The 2023 article is more than three years old and says what the plans were then, not what they are. We use it for one reason: a figure for a free GPTZero plan on an older page can be right for its date and wrong for today. Wikipedia’s sentence is dated September 2025, and we read the pricing page on 6 November 2026.

What GPTZero says about the text you paste

The FAQ answers the question directly for one route. It says GPTZero does not store or collect the documents passed into calls to its API. It then says it does store inputs from calls made from its dashboard, and that this data is used only in aggregate to “further improve the service”. The FAQ does not say whether the scan box on the home page counts as the dashboard, and it does not say how long inputs are kept.

The privacy policy, last updated on 20 May 2026, has a section called User-submitted data. It says text and file contents submitted by API subscribers directly by API are “not stored by default” and are not used for product improvement, and that API subscribers may opt in to having their content stored for viewing in the application. Among the data it lists as collected is submitted content for use of providing the service. The section does not name text that people paste into the site without being API subscribers.

On security, the privacy and security page says GPTZero is SOC 2 Type II compliant and describes its work on GDPR and CCPA. The Chrome page says the extension is compliant with FERPA, GDPR and CCPA, and that personal data is deleted on request. These are statements by GPTZero about itself, and we did not audit them.

The terms of use, last updated on 21 August 2026, say the site is provided on an “AS-IS AND AS-AVAILABLE” basis and disclaim warranties. They also say GPTZero cannot guarantee that the site will be available at all times. For the longer treatment of how this company handles text, see our page on GPTZero; for the same question across other free detectors, see free AI detectors.

What GPTZero says about its results, and one test of the free tool

The FAQ lists the limits of the classifier in GPTZero’s words. Results should not be used to punish students. Accuracy rises as more text is submitted, so it is greater for a whole document than for a paragraph, and greater for a paragraph than for a sentence. It is also higher for text like the training data, most of which is English prose written by adults. The classifier is not trained to identify AI text after it has been heavily modified, and it can sometimes flag other machine-generated or highly procedural text as AI-generated.

On the home page, GPTZero says independent benchmarking shows its Advanced Scan has “best-in-class accuracy”. That is the company’s statement about a scan named on the pricing page, where the Free plan lists one Advanced Scan. Wikipedia reports that in September 2025 Business Insider compared GPTZero with seven other tools and called it the “best free AI detector”; we did not read that article.

Scribbr, which sells its own detector, included GPTZero in a guide published on 22 April 2026 and revised on 21 July 2026. It lists GPTZero as free, with “No sign-up required” to paste in text, and reports an accuracy of 52% in its own test, because in its testing GPTZero gave only binary judgments. That is one test by a company that sells a rival tool, and our copy of the page carried a warning that part of it may not have loaded, so we report only what the text says. Its note about signing up concerns pasting text; the home page’s account rule concerns scans over 10,000 characters.

We do not rank detectors. Our page on Turnitin’s AI detection covers Turnitin’s own AI detector.