Side by side
| PICK | PRICE OR LIMIT | VERDICT | NEED |
|---|---|---|---|
| Pangram | Free: 20 checks a day; Individual USD 20 a month, 300,000 words | Start here | Lowest false positive risk |
| Copyleaks | Personal USD 13.99 a month billed annually, up to 300,000 words | Best for multilingual classes | AI and plagiarism in one report |
| Originality.ai | Pro USD 14.95 a month, or USD 12.95 billed yearly, 200,000 words | Built for content teams | Publisher and website audits |
| Turnitin | Institutional licenses only | Use what your school already has | A school with an existing license |
| None on its own | Not applicable | Use detector output only alongside drafts and a conversation | Deciding a misconduct case |
Our picks in detail
Pangram
Best overall switch; strongest independent false positive evidence
- Best for: teachers, editors and reviewers who need a low false positive rate above everything else.
- Main limitation: Epoch AI found Pangram, like GPTZero and Originality.ai, missed between 10% and 18% of AI passages written to mimic a specific author, and 25% of mimicked scientific writing.
Pangram flagged 0 of 495 human-written passages as AI in Epoch AI's detector test published 15 July 2026.
Copyleaks
Widest language coverage; one report for two questions
- Best for: schools and teams that want AI detection and plagiarism matching in one report, in many languages.
- Main limitation: the Copyleaks pricing page says image scans check for AI only, not image plagiarism, and the Shared Data Hub compares scans against millions of user-submitted documents unless you opt out.
Copyleaks lists AI detection in more than 30 languages on every plan, according to its pricing page on 23 October 2026.
Originality.ai
Full site scans and writing replay; monthly credits expire
- Best for: publishers, agencies and SEO teams checking commissioned or published web copy.
- Main limitation: in Epoch AI's test, Originality.ai wrongly flagged 19 of 495 human passages (3.8%), all written before ChatGPT existed. Subscription credits expire at the end of each month.
Originality.ai Pro costs USD 14.95 a month for 200,000 words, according to its pricing page on 23 October 2026.
Turnitin
Familiar inside the LMS; not sold to individuals
- Best for: instructors at schools that already license Turnitin and want an AI report next to the Similarity Report.
- Main limitation: Turnitin does not sell individual licenses or single-use subscriptions. Individuals are pointed to iThenticate, a credit-based similarity checker.
Turnitin's AI Writing Report requires at least 300 words of prose, according to Turnitin's file requirements guide on 23 October 2026.
Reviewed 23 October 2026 against Pangram, Copyleaks, Originality.ai, Turnitin and GPTZero pricing and help pages, and three published detector evaluations.
Our pick
Pangram wins because two independent evaluations put its false positive rate at or near zero. In Epoch AI's July 2026 test of three detectors, Pangram and GPTZero flagged none of 495 human passages as AI. A 2025 NBER working paper by Jabarian and Imas found Pangram was the only tool tested to meet a strict cap of a 0.5% false positive rate without sacrificing accuracy. The Pangram pricing page lists Individual at USD 20 a month for up to 300,000 words. The trade-off: in Epoch's test Pangram missed 25% of AI passages written to imitate scientific authors.
Switching from GPTZero: what it does well and why people leave
GPTZero remains a strong detector. Its pricing page offers a free plan of 10,000 words a month, and the Professional Team plan allows 500,000 words per member a month, with a minimum of 2 seats and card payment only. If that covers your work, our GPTZero review explains which plan fits.
People switch for four documented reasons:
- Ownership. GPTZero is now part of Superhuman, the company that also owns Grammarly. Some schools and publishers prefer a detector with no writing-assistant sibling.
- Training data. GPTZero's FAQ says the majority of its dataset is English prose written by adults, which matters for younger and second-language writers.
- Plagiarism in one report. Copyleaks and Originality.ai bundle AI detection with plagiarism matching on every paid plan.
- Institutional workflow. Many schools already see Turnitin's AI Writing Report inside their learning management system.
GPTZero's free plan allows 10,000 words a month, according to GPTZero's pricing page checked on 23 October 2026.
What independent tests say about false positives
No AI detector score should be the only evidence in a misconduct case.
Three sources shape this ranking:
- Current detectors rarely flag plain human text. Epoch AI found Pangram and GPTZero flagged none of 495 human passages, and Originality.ai flagged 3.8% (July 2026).
- Imitated writing slips through. The same test found detectors missed 10% to 18% of AI text written to imitate a specific author.
- Older detectors penalized non-native writers. Liang and colleagues found GPT detectors misclassified non-native English writing as AI-generated while classifying native writing accurately (Patterns, 2023).
The 2023 study covered older detector versions, and vendors have retrained since. The pattern still matters: a false accusation costs a student far more than a missed flag costs a teacher. Our guide to AI detector false positives explains what to do if you are flagged.
Where GPTZero alternatives fall short
None of these is a full GPTZero replacement. Pangram has the strongest evidence, but GPTZero bundles authorship reports and writing replay in the same product. Copyleaks and Originality.ai mix two questions, overlap and AI authorship, in one score sheet. Turnitin is closed to individuals. GPTZero itself matched Pangram's zero false positives in Epoch's test, so switch for workflow, language or ownership reasons, not because GPTZero is careless. ZeroGPT is a separate product from a separate company despite the similar name; our ZeroGPT vs GPTZero comparison sets the two side by side.
How we picked
- We compared each detector's documented plans, prices, free limits, word allowances, languages and report features, using vendor pricing and help pages read on 23 October 2026, and weighted independent false positive evidence from Epoch AI (495 human passages, July 2026) and Jabarian and Imas (NBER, 2025). Both tests used fixed corpora that may not match your students' writing, and Epoch counted only a clean "AI" verdict as a flag. Our full method is on the HumanRank ranking methodology page.
How to choose
How to choose
- Collect three labeled sets: human writing you can vouch for, AI text, and AI text a person has edited.
- Run each set through the free tiers of Pangram and Originality.ai.
- Count false positives and missed AI text separately, rather than one accuracy number.
- Check language support against your students' or writers' languages.
- Price a year: Pangram Individual, Copyleaks Personal at USD 167.88, or Originality.ai Pro billed yearly.
- Write down how a flag will be used before the first scan.
For the full field, see our AI detector rankings, the Copyleaks review, the Originality.ai review and the Turnitin AI detection review. Teachers can start with our guide for educators, and GPTZero vs Copyleaks covers the most common head-to-head. If you only need a detector that costs nothing, our free AI detectors ranking compares the free plans on their own.
Questions people ask
What is the best free GPTZero alternative?
Pangram, with 20 free checks a day after sign-up. Originality.ai's free tier is a one-time 10,000 words.
Is Pangram more accurate than GPTZero?
On human text, they tied in Epoch AI's test: neither flagged any of 495 human passages. The NBER paper found only Pangram met a 0.5% false positive cap.
Which GPTZero alternative checks plagiarism too?
Copyleaks and Originality.ai both bundle AI detection with plagiarism checks.
Can I buy Turnitin as an individual?
No. Turnitin sells only to schools, universities and organizations, and points individuals to iThenticate.
Which AI detector supports the most languages?
Copyleaks, with AI detection in more than 30 languages. Pangram lists more than 20.
Is GPTZero owned by Grammarly?
GPTZero and Grammarly are both part of Superhuman, which announced that GPTZero had joined the company.
Can a detector prove a student used AI?
No. GPTZero's own FAQ says results should not be used to punish students, and independent tests show every detector makes errors.
Which GPTZero alternative is cheapest?
Of the plans listed here, Originality.ai Pro at USD 12.95 a month billed yearly. Copyleaks Personal costs USD 13.99 a month billed annually.
Sources
- [1]July 2026 test of three detectors epoch.ai · 23 Oct 2026
- [2]2025 NBER working paper by Jabarian and Imas nber.org · 23 Oct 2026
- [3]Pangram pricing page pangram.com · 23 Oct 2026
- [4]pricing page gptzero.me · 23 Oct 2026
- [5]GPTZero is now part of Superhuman blog.superhuman.com · 23 Oct 2026
- [6]FAQ gptzero.me · 23 Oct 2026
- [7]homepage pangram.com · 23 Oct 2026
- [8]Copyleaks pricing page copyleaks.com · 23 Oct 2026
- [9]Originality.ai pricing page originality.ai · 23 Oct 2026
- [10]does not sell individual licenses or single-use subscriptions helpcenter.turnitin.com · 23 Oct 2026
- [11]file requirements guide guides.turnitin.com · 23 Oct 2026
- [12]GPT detectors misclassified non-native English writing as AI-generated arxiv.org · 23 Oct 2026