Minute Verdict
GPTZero is an AI detector that marks the sentences it believes a model wrote, then wraps that verdict in a report a teacher or an editor can keep. The entry paid plan is Premium at $23.99 a month, or $12.99 a month billed yearly for $155.88 a year, and it covers 300,000 words a month.
Best for: a department or a publisher that needs a dated report per document, with a plagiarism check and a writing replay in the same place.
Not for: one person checking a handful of essays a month, who will exhaust the 10,000 word free tier and pay a monthly rate that is close to double the annual one.
What GPTZero does
GPTZero takes a text or a file and returns a probability that a model wrote it, sentence by sentence, with the flagged passages highlighted. The Advanced Scan adds a written report: the share of the document judged AI, the passages that drove the verdict, and the reasoning in plain language. The company sells four more jobs on top of that: a plagiarism check against online and academic sources, an authorship and writing replay that records how a Google Docs document was typed, a source finder that flags citations that may not exist, and a grammar and writing feedback pass.
The tool is built for classrooms first. It plugs into Google Docs, the Chrome extension, Canvas and Google Classroom, and the homepage is written for teachers and students rather than for marketers. A separate AI Vision product, launched in February 2026, highlights AI-generated material on a social feed, which is a different buyer and a different job.
On the numbers, GPTZero reports 20 million accounts and 2 million educators, and says it was founded in January 2023 by Edward Tian, then a Princeton student. Those are company figures, repeated on its own pages.
On this page
What you get for the money
| Plan | Price | Words a month | The limit that matters |
|---|---|---|---|
| Free | $0 | 10,000 | 10,000 characters per scan, one Advanced Scan, five Chrome highlights |
| Premium | $23.99 monthly, $12.99 billed yearly | 300,000 | 50,000 characters per scan |
| Professional | $45.99 monthly, $24.99 billed yearly | 500,000 | 150,000 characters per scan, 250 files at once, overage to 2,000,000 words |
| Team | Professional per seat, two seats minimum | 500,000 per member | Card payment only, no invoicing |
The unit that decides your bill is the word, not the document, so a 4,000 word paper counts as 4,000 against the monthly allowance whatever it costs you to review. On Premium, a year at the monthly rate comes to $287.88 against $155.88 billed yearly, for the same 300,000 words a month. The difference is not a discount for loyalty: the monthly rate is the price of being able to leave after four weeks.
At the top, the Professional plan allows a 2,000,000 word overage and batches of 250 files, which is the plan for a department processing a submission window rather than a person reading drafts. A separate API is priced from $45 a month for 300,000 words, rising to $1,850 a month for 20,000,000 words.
Where it falls short
- The free tier is a sample, not a plan. 10,000 words a month is roughly a long essay a week, and a single scan stops at 10,000 characters, so a thesis chapter has to be split before it can be checked.
- Monthly billing is close to double. $23.99 against $12.99 a month billed yearly, $45.99 against $24.99 on Professional. Anyone who needs one month of work pays the annual rate plus about 85%.
- The accuracy figure is the company’s own. 99.9% is stated on the homepage and in the FAQ. The RAID benchmark it cites, 95.7% of AI texts caught with 1% of human texts flagged, is summarised by GPTZero, and no independent test is published on the site.
- Retention is detailed for one path only. The privacy notice says API submissions are not stored by default and are not used for improvement, and that data is kept no longer than three months after an account closes. Text pasted into the dashboard does not get the same explicit paragraph.
- The Team plan is card only. Two seats minimum, no invoicing or purchase orders through the checkout, which pushes schools and public bodies toward a sales conversation.
GPTZero alternatives
- Copyleaks, $16.99 a month on the monthly view, or $13.99 a month billed yearly at $167.88 a year: 25,000 words a month on the monthly plan against 300,000 on the annual one, with AI and plagiarism detection in a single report and 30 languages. The priced study tools are the closest place to compare the two.
- Originality.ai, $14.95 a month, or $12.95 a month billed yearly: 200,000 words a month, a pay as you go credit model and a free 100 credit try. Built for content teams rather than for classrooms, which is why it sits next to the SEO and content hub.
- Pangram, $20 a month with a 7 day free trial: 300,000 words a month, image detection on every plan and no annual commitment required. The closest match on volume, and the only one of the three that scans images as well as text, which is why it also sits with the priced study tools.
GPTZero’s difference is the report and the classroom plumbing. Its weakness is that its cheapest paid month costs more than two of these three competitors.
Who it is for: GPTZero
GPTZero fits an institution that has to answer a question in writing. A department head who receives a disputed essay, a publisher who needs a record of what was checked and when, an editor who wants the flagged sentences rather than a single score: the report is the product, and 300,000 words a month covers a real caseload. The free tier is enough to see whether the verdicts agree with your own reading of ten texts, which is the only calibration that matters before you pay.
It is a poor fit for one teacher with two classes, who will run out of words in the first week and gain nothing from the Professional overage. It is also a poor fit for teams that need invoicing, since the Team plan takes cards only. And it is a poor fit for anyone who wants a verdict in dollars per thousand words: Copyleaks at $16.99 and Originality at $14.95 both sell a bigger monthly allowance for less, and Pangram matches 300,000 words at $20 with no annual commitment.
How we checked
We read the pricing page in its monthly and annual views on November 9, 2026, the plan entries behind it, the public FAQ, the privacy notice updated May 20, 2026 and the support article on cancellation, all on the same day. We created no account, scanned no text and ran no document through the detector, so nothing on this page describes a result we measured. Every accuracy figure here is attributed to the company. The page becomes a hands-on review when we have run a set of known texts through it and can publish what came back.
Timeline
- January 2023: GPTZero is founded by Edward Tian, per the company FAQ.
- February 2026: AI Vision launches, per the Superhuman announcement of the acquisition.
- May 20, 2026: the privacy notice is updated, with a three month retention cap after account closure.
- June 23, 2026: Superhuman announces it has agreed to acquire GPTZero, in a dated post on its own blog.
What to do next
Start on the free tier with ten documents you already know the answer to, and compare the flagged sentences against your own reading. If the verdicts hold, price the volume you actually process: 300,000 words a month on Premium is a lot of essays, and the monthly rate only makes sense if you plan to leave. If you need more than 500,000 words, compare the Professional overage with Copyleaks and the other priced detectors we follow before committing to a year. The GPTZero alternatives page lists what we would try instead, and how we test explains what a hands-on verdict will add.
FAQ
How much does GPTZero cost? Premium is $23.99 a month, or $12.99 a month billed yearly for $155.88 a year, with 300,000 words a month. Professional is $45.99 a month, or $24.99 a month billed yearly for $299.88, with 500,000 words. The free plan gives 10,000 words a month.
Is GPTZero free? Up to 10,000 words a month, with a 10,000 character limit per scan, one Advanced Scan and five highlights in the Chrome extension. Above that, a paid plan is required.
Is GPTZero accurate? GPTZero claims 99.9% accuracy, 95.7% detection on the RAID benchmark with 1% of human texts flagged, and 96.5% on mixed documents. Those are company figures and benchmarks summarised by the company, not an independent audit.
Does GPTZero store the text I paste? The privacy notice says API submissions are not stored by default and are not used for product improvement unless the subscriber opts in, and that data is kept no longer than three months after an account closes. The notice does not give the same explicit rule for text pasted into the dashboard.
Who owns GPTZero? GPTZero LLC, based in New York. Superhuman, formerly Grammarly, announced an agreement to acquire the company on June 23, 2026.
How do I cancel GPTZero? Settings, then Manage Plan, then Cancel Plan, confirmed in the Stripe billing page. Access continues to the end of the billing period, and documents older than 30 days become inaccessible after that.
Sources
Sources
- GPTZero pricing (checked November 9, 2026), the four plans, the monthly and annual rates, the word and character limits
- GPTZero home (checked November 9, 2026), the product scope, the accuracy and user figures, the integrations
- GPTZero privacy notice (checked November 9, 2026, notice updated May 20, 2026), retention and API submissions
- Cancellation and refund article (checked November 9, 2026), the cancellation path and the 30 day document window
- Superhuman announcement (published June 23, 2026, checked November 9, 2026), the acquisition and the AI Vision launch
Update log
Published November 9, 2026 as a research review. Prices read on the US pricing view the same day, monthly and annual.
