ZeroGPT Review (2026): Accuracy, Pricing and the Best Alternative

ZeroGPT is a free AI detector that checks up to 15,000 characters at a time and comes bundled with a humanizer, a plagiarism checker and other writing tools. The bottom line of this ZeroGPT review: it is convenient, but its accuracy figures are self-reported and research has caught it flagging human writing. Our top pick is Essai.

Essai pairs a free AI detector with an AI humanizer in one web app, so you can revise an AI-assisted draft and check it in a single workflow. Below you will find ZeroGPT's features, prices as of October 2026, accuracy record and public ratings, plus the reasons Essai is the better choice for students and writers. ZeroGPT changes its plans from time to time, so confirm the details on its pricing page before you pay.

ZeroGPT at a glance

Pros and cons

Pros

• Roomy free checks. The free detector accepts up to 15,000 characters per scan, and paid plans raise the cap to between 100,000 and 350,000 characters.
• Sentence-level highlights. Each result pairs an overall AI percentage with highlighted sentences, so you can see which passages pushed the score up.
• Clear privacy terms. ZeroGPT's Terms of Use and Privacy Policy say private user content is not used to train its models, and its FAQ says checked text is not saved, shared or published.

Cons

• Self-reported accuracy. The headline 98.4 percent accuracy and under 1 percent false positive rate are labeled as ZeroGPT's own product metrics, and ZeroGPT never names the evaluation behind them.
• Documented false positives. Researchers and journalists have recorded ZeroGPT labeling human writing as AI-generated, from essays by non-native English writers to part of the US Constitution.
• A stripped-down free plan. Free users see ads and get no batch uploads, PDF reports or scan history, and the plagiarism allowance is a one-time 300 words.
• A 10-hour refund window. Refund requests must arrive within 10 hours of a first subscription purchase (12 hours for an accidental annual purchase), and only one refund is allowed per customer.
• Poor public reviews. ZeroGPT's unclaimed Trustpilot profile shows a TrustScore of 1.2 out of 5 from 111 reviews as of October 2026, with 98 percent of ratings at one star.
• A third-party humanizer with no promises. ZeroGPT says its Advanced humanizer model is provided by Undetectable AI, and its Terms say it does not guarantee that humanized text will pass ZeroGPT or any other detector.

Key features

AI detector

Paste text or upload a .txt, .docx or text-based PDF file, and ZeroGPT returns an overall AI percentage with the suspect sentences highlighted. Free checks stop at 15,000 characters. The ZeroGPT FAQ asks for at least 150 to 200 words, says 500 to 1,000+ words give steadier results and suggests running OCR on image-based PDFs first.

ZeroGPT says its DeepAnalyse model reads a document from broad patterns down to single sentences, covers 35+ LLM families including ChatGPT, Gemini, Claude, Grok, DeepSeek and LLaMA, and supports all languages. Batch uploads (50 to 100 files, depending on the plan), downloadable PDF reports and scan history are reserved for paying customers.

AI humanizer

The free Basic humanizer rewrites pasted text and comes with a "Check for AI" button. The same page then pushes an Advanced model that ZeroGPT says is provided by Undetectable AI, a tool we cover in our Undetectable AI review. ZeroGPT's own Terms say it does not guarantee that humanized text will pass ZeroGPT, pass another detector or meet academic requirements. If your course or employer limits AI use, their policy comes first.

Plagiarism checker

The plagiarism checker needs an account, and the entry allowances are thin: a one-time 300 words on Free and 750 words on Pro. Plus, Max and Expert get 35,000, 60,000 or 150,000 words a month, and EDU gets 1,200,000 words a year. Scan counts are capped as well, and extra words cost $0.70 per 1,000 on Free and Pro or $0.40 per 1,000 on higher plans, as of October 2026.

Extras

• Image and video detection. The image detector takes JPG, PNG or WEBP files or a public image URL, and the video detector takes MP4, MOV, AVI, MKV and WEBM files up to 100 MB. ZeroGPT says both run on TruthScan, and video detection is a paid feature.
• Writing tools. A paraphraser, summarizer, grammar checker, translator, word counter, citation generator, dictionary, email helper and the ZeroCHAT chatbot. Max, Expert and EDU subscribers can also use ZeroGPT inside WhatsApp and Telegram.
• API. Pay-as-you-go access with a prepaid balance, starting at $0.042 per 1,000 words for AI detection on the entry Beginner tier as of October 2026. The Terms say API credits are non-refundable.

ZeroGPT pricing (as of October 2026)

ZeroGPT sells a free tier, three personal plans (Pro, Plus and Max) and three business plans (Expert, EDU and Enterprise). The figures below are what its pricing page showed US visitors as of October 2026. The page picks the currency by location, so visitors elsewhere may see euros or different amounts.

How Essai compares: Essai's AI detector is free, and a free account adds detailed reports and unlimited scans, while ZeroGPT holds back PDF reports and scan history until you pay. For the same $14.99 a month as ZeroGPT Pro, Essai Basic includes 5,000 humanizer words a month and unlimited AI detection, as of October 2026.

Before you subscribe to ZeroGPT, know these rules:

• Annual discount. The page advertises 40 percent off for annual billing. Based on the listed US prices, that holds for Pro, while Plus, Max and Expert work out to about 35 to 36 percent off.
• Detection allowances. Every plan carries an AI-detection word allowance, from 1,250,000 words a month on Free to 15,000,000 on Expert (EDU gets 70,000,000 a year).
• Refunds. The Terms of Use, updated October 7, 2026, allow a full refund request within 10 hours of a first subscription purchase, or within 12 hours for an accidental annual purchase. Renewals and partly used periods are excluded, and the FAQ still lists shorter windows of 6 and 10 hours.
• Cancellation. Canceling from the Subscription section of your account stops renewal, and you keep access until the paid period ends.
• EDU is annual only. The EDU plan cannot be billed monthly.

Is ZeroGPT accurate?

ZeroGPT's accuracy is hard to verify. Its headline numbers come from ZeroGPT itself, while outside research and reporting have caught it labeling human writing as AI. Treat a ZeroGPT score as a hint, not proof.

What ZeroGPT claims

ZeroGPT says its DeepAnalyse model reaches 98.4 percent detection accuracy with a false positive rate below 1 percent. The DeepAnalyse page labels these as ZeroGPT product metrics and keeps model details private. It describes the accuracy figure as the share of correct classifications "in the referenced evaluation," yet it never names that evaluation or links to an outside one. The FAQ says accuracy is pushing toward more than 98 percent on internal evaluations and that the model is retrained regularly.

ZeroGPT also concedes the limits of its own scores. Its DeepAnalyse FAQ answers the question "Does a high AI score prove that AI was used?" with a plain "No," and its Terms of Use say no detector, ZeroGPT included, can determine authorship with absolute certainty in every case. The same Terms bar users from treating a score as the only basis for decisions about someone's education, job or admission.

What outside research and reporting found

• Bias against non-native writers. In a 2023 Stanford study later published in Patterns, Liang and colleagues ran 91 TOEFL essays by non-native English writers and 88 essays by US eighth graders through seven widely used detectors, ZeroGPT among them. The detectors were near-perfect on the US essays but averaged a 61.22 percent false-positive rate on the TOEFL essays, and all seven, ZeroGPT included, labeled 18 of the 91 human-written TOEFL essays as AI-authored.
• Famous human texts flagged. In screenshots published by Ars Technica in July 2023, ZeroGPT returned "Your text is AI/GPT Generated" for part of the US Constitution and rated a passage from the Book of Genesis 88.2 percent AI-generated.
• Weak results in a 14-tool study. A 2023 study in the International Journal for Educational Integrity tested 14 detection tools, ZeroGPT among them, concluded that they are "neither accurate nor reliable," and found that none of the 14 reached 80 percent accuracy.

These findings are snapshots, and ZeroGPT says it retrains its model regularly. Until it links to an outside evaluation, though, its headline numbers are claims you have to take on trust.

Why ZeroGPT flags human writing

ZeroGPT's FAQ says its detector reads statistical signals such as token patterns, burstiness and entropy. Human writing can trip those signals in a few predictable ways:

• Formal or formulaic prose. Ars Technica points out that people write predictably too, especially in academic styles, and ZeroGPT's FAQ admits that polished, formulaic writing can resemble AI.
• Limited vocabulary. Liang and colleagues found that the TOEFL essays every detector flagged had significantly lower perplexity, and they warn that detectors may penalize writers with more constrained language, such as people writing in a second language.
• Famous texts. As Ars Technica's reporting explains, documents like the Constitution appear so often in training data that language models learn to produce similar text, so detectors read the originals as machine-like.
• Short or heavily edited samples. ZeroGPT says short or heavily edited snippets give its detector fewer signals to work with.

If you grade student work, treat a ZeroGPT score as a reason to talk with the student, not as a finding. Our guide to checking student essays for AI lays out a fairer process, and AI detection false positives explains what to do if your own writing gets flagged.

How Essai's detector compares

Essai's free AI detector returns an AI probability score from 0 to 100 percent and works best on 150 words or more, and a free account adds detailed reports and unlimited scans. In Essai's internal testing, our detector outperformed ZeroGPT on many of the criteria we track.

What users say

ZeroGPT's unclaimed Trustpilot profile shows a TrustScore of 1.2 out of 5 from 111 reviews as of October 2026, with 98 percent of ratings at one star. Most recent reviews describe the same problems:

• Human-written essays and documents flagged as AI-generated.
• Scores that swing after small edits or disagree with other detectors.
• Billing and refund trouble, raised by a smaller group of reviewers, along with a few who say the humanizer oversimplified their writing.

The false-positive theme lines up with the research above.

What Essai users say

"I've tested many alternatives, but nothing comes close to the quality Essai provides." (Priya Sharma, Essai user)

"Essai has greatly simplified my physics studies. The ability to humanize essays while keeping my original meaning intact has been incredibly helpful for my assignments." (Marcus Thompson, Essai user)

"I used to spend hours rewriting essays. Now Essai does it in seconds. The text humanizer is incredibly accurate and saves me so much time on every assignment." (Robert Kim, Essai user)

ZeroGPT vs Essai

Both tools give you a free AI detector and a humanizer. Here is how they compare on public facts as of October 2026.

Why Essai is the better ZeroGPT alternative

• Detailed reports for free. A free Essai account adds detailed reports and unlimited scans, while ZeroGPT keeps PDF reports and scan history behind a paid plan.
• Unlimited AI detection on every plan. Basic, Pro and Ultra all include unlimited AI detection, so you never have to watch a detection word allowance.
• A humanizer that keeps your meaning. Essai's AI humanizer is designed to keep what you mean while making phrasing, rhythm and word choice read naturally, so AI-assisted text reads as human-written. It is built to help your text pass popular AI detectors.
• One workflow, two tools. Humanize a draft on the home page, then check it with the detector in the same app, without copying text between services.
• Simple pricing. Three paid plans, Basic, Pro and Ultra, with about 30 percent off for yearly billing as of October 2026. ZeroGPT splits its offer into seven tiers and sets the currency by where you browse from.
• Free to start. Humanize up to 125 words per request with no signup or credit card, and run the detector at no cost.

Best ZeroGPT alternatives

Want the full field? Our best AI detectors guide ranks the top tools. Here are the strongest ZeroGPT alternatives, starting with our pick.

1. Essai (best overall). A free AI detector with a 0 to 100 percent probability score, unlimited scans and detailed reports on a free account, plus an AI humanizer in the same app. Paid plans start at $14.99 a month, or $9.99 a month billed yearly, as of October 2026.
2. GPTZero. Sentence-level AI detection with a free plan of 10,000 words a month. Premium costs $23.99 a month, or $12.99 a month billed annually, as of October 2026. It has no AI humanizer, and Trustpilot reviewers repeatedly describe unexpected charges.
3. Copyleaks. AI and plagiarism checks in one report, with no-login AI scans of up to 25,000 characters. Credits round up in 250-word blocks, there is no AI humanizer, and its TrustScore stood at 2.7 out of 5 from 365 reviews in October 2026.
4. Originality.ai. A content-checking suite for publishers and editors, with three free AI scans a day of up to 2,000 words. Pro starts at $14.95 a month as of October 2026, and paid credits lapse when each billing cycle closes.
5. Winston AI. An AI and plagiarism checker aimed at educators. Its free option is a 14-day trial with 2,000 credits, paid plans start at $18 a month as of October 2026, and it has no AI humanizer.

ZeroGPT review verdict

ZeroGPT is a convenient free scanner with a long list of extras, but it falls short where a detector matters most: trust. Its accuracy figures come from ZeroGPT itself, research and reporting have documented false positives on human writing, and its Trustpilot rating sits at 1.2 out of 5 as of October 2026. Essai gives you a free AI detector with detailed reports and unlimited scans on a free account, plus an AI humanizer designed to keep your meaning while your text reads naturally. That is why Essai is our top pick and the best ZeroGPT alternative for students and writers in 2026.