By The detector to buy if you publish for a living. Best-in-class paraphrase detection, a site scanner nobody else offers, team seats, an API, and a company that answers every negative review. The credit system is more expensive than it looks for people who revise, and the false-positive rate is several times the marketing claim. Not for schools.
- Best for
- Publishers, agencies, editors screening freelance work
- Skip if
- You are a school (no FERPA or SOC 2), or you want a free tool for occasional checks
- Price
- $14.95/mo Pro, 2,000 credits (200,000 words); $179/mo Enterprise
- Trustpilot
- 4.6 from 1,334 reviews
Key takeaways
If you remember three things: it has the best published result on paraphrased text (96.7 percent on RAID), one credit equals 100 words and rescans cost credits again, and third parties measure false positives at roughly five percent rather than the one percent on the marketing page. Everything else below is detail.
Pros and cons
Why publishers buy it
- Best paraphrase detection on a public benchmark
- Full-site scan, unique in the category
- Team seats, shared history, API on Enterprise
- Three detection models to tune sensitivity
- Plagiarism, readability, fact-check aid and Chrome extension bundled
- 4.6 Trustpilot, replies to 100 percent of negative reviews, clear refund policy
Why some return it
- Rescans of edited text spend credits again
- Real false-positive rate several times the claim
- Formal and Grammarly-edited writing gets flagged
- Not SOC 2 or FERPA certified
- Pro is pricey for a solo writer who scans occasionally
- Some vendor accuracy figures could not be traced to primary sources
What Originality.ai does
Founded in November 2022 by Jon Gillham, who had built and sold a content marketing agency and wanted a way to check whether freelancers were handing in GPT-3 output, Originality.ai launched weeks before ChatGPT made the problem universal. The core is an AI detector with three models: Lite, tuned for a claimed 0.5 percent false-positive rate; Turbo, tuned for paraphrased content; and Academic, with stricter thresholds. Around it sit a plagiarism checker, a readability scorer, a fact-checking aid that flags claims for verification, a Chrome extension that works inside Google Docs and WordPress, a full-site scan that crawls a domain and scores every page, and on the Enterprise tier an API and team dashboards. It is a publisher's toolkit with a detector at its centre, which is a different product from the student-facing tools.
Where this review's figures come from
We traced every accuracy figure we could find back to who produced it: the RAID academic benchmark, Scribbr's independent comparison (which is dated and which Scribbr, a competitor, ran), third-party reviewers who measured false positives, and the company's own claims. We read the pricing page and did the credit arithmetic on three realistic workflows. We read the refund policy, the affiliate terms, and the complaint themes across 1,334 Trustpilot and 247 G2 reviews. Where the company's numbers are the only ones available, we say so.
Accuracy: vendor claims versus independent tests
| Measure | Company claim | Independent result | Source |
|---|---|---|---|
| Accuracy on AI text | 99%+ | 76 to 92% | Multiple third-party tests |
| RAID benchmark | 85% overall | Academic benchmark, Oct 2025 entry | |
| Paraphrased text | 97% (Turbo) | 96.7% | RAID |
| False positives | 0.5 to 1.5% | 4.8 to 5.7%; up to 28% in ESL samples | Third-party reviewers |
| Scribbr comparison (2024) | 76% | Scribbr, a competitor, dated |
Three things stand out. The paraphrase result is real and it is the best in the category; if your worry is content that has been spun or lightly humanized, this is the detector with the evidence. The headline accuracy claim is marketing, as every vendor's is, and the independent range of 76 to 92 is still strong. And the false-positive gap matters: five percent of a freelance pool of forty writers is two people wrongly accused a month, and the G2 reviews describing Grammarly-edited and formal prose being flagged are consistent with the known behaviour of every detector. Pick the Lite model if that worries you more than a miss.
One figure we deliberately left out: a widely repeated "GPT-5 detection" percentage for Originality.ai that we could not trace to a primary source. If a number cannot be sourced, it does not go in our table.
Pricing and the credit maths
Originality.ai bills in credits. One credit scans 100 words of AI detection. Plagiarism scans use two credits per 100 words. Deep Scan uses more. And, the part people miss, scanning the same article again after edits spends credits again.
The credit model is the thing we would change if we ran the company. It taxes exactly the behaviour a detector should encourage: scan, fix, scan again.
| Plan | Monthly | Annual (per month) | Credits | Words of AI detection | Includes |
|---|---|---|---|---|---|
| Basic (free) | $0 | $0 | 60/mo | 6,000 | 3 scans a day, 2,000-word cap, AI only |
| Pro | $14.95 | $12.95 | 2,000/mo | 200,000 | All tools, extension; extra seats $9.95 |
| Enterprise | $179 | $136.58 | 15,000/mo | 1,500,000 | API, 365-day history, seats $24.95 |
| Pay-as-you-go | $30 one-off | 3,000 | 300,000 | 2-year expiry; not shown on current page, verify |
Three worked examples. A solo blogger publishing eight 1,500-word posts a month and scanning each once uses 120 credits; the free tier's 60 does not cover it, so Pro at $14.95 is the entry point and 94 percent of the credits go unused. An editor screening 40 freelance pieces of 1,200 words, each scanned twice (draft and revision) plus plagiarism on the final, uses roughly 40 × (12 + 12 + 24) = 1,920 credits, right at the Pro ceiling. An agency scanning 300 pieces a month with plagiarism is into Enterprise territory, where the API and history justify the price. The lesson is that Pro is generous for individuals and tight for editors who revise, and the credit model punishes exactly the careful workflow the tool is supposed to support.
The refund policy is public and reasonable: case by case for service disruptions or billing errors, with a refund expiring remaining credits. You can cancel any time and keep access until the period ends. Subscription credits expire at month end, so do not stockpile.
Team and API features
This is where Originality.ai separates from GPTZero for professional use. Shared scan history lets an editor see what a writer already checked. Seats are cheap at $9.95 on Pro. The Enterprise API supports batch scanning so you can wire detection into a CMS workflow, and the 365-day history means audit trails. The full-site scan is the feature no competitor offers: point it at a domain and it crawls and scores every page, which is how agencies audit a site they have just inherited and how publishers check whether a programmatic section has drifted. None of this matters to a student, which is the point.
What users say
Trustpilot: 4.6 out of 5 from 1,334 reviews, 81 percent five-star, and the company replies to every negative review, which is rare enough to mention twice. The complaints that exist are about human text being flagged. G2: 4.4 from 247 reviews, with praise for accuracy and the extension, and complaints about price for small teams, credits being re-spent on rescans, false positives on formal or Grammarly-edited text, and occasional extension and login glitches. Both profiles describe a company that is responsive and a product whose main flaw is the one every detector has.
Originality.ai vs GPTZero vs Copyleaks vs Winston
| Originality.ai | GPTZero | Copyleaks | Winston AI | |
|---|---|---|---|---|
| Paid from | $14.95/mo | $14.99/mo | $16.99/mo | $18/mo, $60/yr |
| Free tier | 60 credits/mo | 10,000 words/mo | Not shown | 14-day trial |
| Independent accuracy | 76 to 92%; 96.7% paraphrased | 52 to 95% | 65 to 66% | Not published |
| False positives | 4.8 to 5.7% | 1 to 12% | 1 to 2% | Not published |
| Site scan | Yes | No | No | No |
| API | Enterprise | Professional+ | Yes | Yes |
| Education compliance | No | SOC 2, FERPA | LMS integrations | Google Classroom |
| Trustpilot | 4.6 | 2.2 | n/a | n/a |
Our detector comparison covers all eight tools we rate, and our GPTZero review goes deeper on the main alternative.
Who should use it, and who should skip
Use it if you publish, edit or run an agency: the paraphrase detection, site scan, seats and API are built for you and the support record means you will be looked after. Start on Pro, pick the Lite model if false positives worry you, and budget credits for rescans. Skip it if you are a school (no FERPA, no SOC 2, and GPTZero's LMS integrations are better), if you scan a handful of things a month (the free tier or QuillBot will do), or if you need audited rather than vendor-reported accuracy for a high-stakes decision, in which case no detector qualifies.
Questions readers ask about Originality.ai
How accurate?
76 to 92 percent independently on plain AI text, 96.7 on paraphrased. False positives around five percent, not the one percent advertised.
How do credits work?
One credit per hundred words. Pro is $14.95 for 2,000. Rescans spend again, plagiarism costs double.
Free tier?
Sixty credits a month, three scans a day. Enough to check a few articles.
Better than GPTZero?
For publishers, yes. For schools, no: no FERPA, no SOC 2, no LMS integration.
False positives?
Yes, especially on formal and Grammarly-edited writing. Use the Lite model if that worries you more than a miss.
Refunds?
Case by case, mainly for billing errors or outages. Cancel any time, keep access to period end, credits expire monthly.
Verdict
Originality.ai is the detector we would buy for a publishing business and the one we would not buy for a school. The paraphrase detection is the best evidenced in the category, the site scan and team features have no real competitor, and the company's customer record is excellent. Go in knowing that the real false-positive rate is around five percent rather than one, that revising costs credits, and that no detector, this one included, should decide anything about a person on its own.