GPTinf
GPTinf is a Ukrainian-built web platform bundling six writing tools: an AI detector, humanizer, paraphraser, plagiarism checker, readability checker and grammar checker. The detector runs free and unlimited, with no account required.
What is GPTinf?
GPTinf is a browser-based writing platform that gathers six tools behind one account: an AI detector, an AI humanizer, a paraphraser, a plagiarism checker, a readability checker and a grammar checker, alongside an essay writer. The site sums the pitch up as "Six tools. One platform. Your draft walks out clean."
The AI detector is the entry point and the most generous part of the product: it is advertised as free and unlimited, with no registration, no paywall and no word cap. It tests text against structural patterns, probability signals and AI watermarks drawn from ChatGPT, Gemini, Claude, DeepSeek and Grok, cross-checking eight systems. Every sentence comes back labelled AI, Mixed or Human with an explanation of what triggered the flag, and a breakdown shows the percentage match against each major model.
The humanizer is the paid centrepiece. GPTinf says it runs its own engine, trained on human and AI writing side by side, and that it edits text directly rather than passing it through another language model. The rewrite is structural: each sentence gets a new grammatical subject, verb constructions change, clauses move, and sentences split or merge. Two registers are documented, Standard and Academic, and a Freeze Keywords function locks names, citations and brand terms so they survive the rewrite. Every output carries a detection score underneath it, and any selected passage can be re-humanized on its own. Files can be uploaded as PDF, Word or plain text.
Eleven languages are claimed at 90%+ accuracy for detection and humanization, and the interface itself ships in nine locales. The company behind it is a Ukrainian sole proprietorship registered as Zhdan A. V. in Lviv, founded in 2023 and now a team of ten or more; it reports over 500,000 monthly visitors and more than 15 billion words humanized. GPTinf publishes a responsible-use page that discourages academic dishonesty and concedes that no service is 100% undetectable, a caveat worth weighing against the guarantee language used elsewhere on the site.
What it does
- Detect AI-generated text and score it sentence by sentence as AI, Mixed or Human
- Rewrite AI-sounding drafts so they read as human-written
- Paraphrase passages while preserving the original meaning
- Check text for plagiarism against web sources and trace each match to its URL
- Correct grammar and punctuation, including contextual errors
- Measure readability with a Flesch-Kincaid score and flag hard-to-read passages
- Draft an essay from scratch with the essay writer
When to use GPTinf / When not to
A quick filter to help you decide if GPTinf is the right fit.
When to use GPTinf
- Students who want to check an essay for AI signals and plagiarism before they hand it in.
- Teachers, professors and graders who need to spot AI involvement in submitted work.
- ESL writers who draft in structured English and want the phrasing to read naturally.
- Content marketers and SEO writers who scale drafts with AI and need them to match a brand voice.
- Occasional users on a tight budget: the detector costs nothing and the cheapest paid tier starts at 4.99 USD per month.
When not to use GPTinf
- Developers, because GPTinf publishes no API and offers no programmatic access whatsoever.
- Mobile-first users, since there is no iOS or Android app and no browser extension.
- Enterprise and public-sector buyers, who will find no DPA, no security certification and no named GDPR representative.
- Organisations that must keep data inside the EU: the vendor states its servers sit in the United States, with no regional option.
- Anyone under 18, who is barred by both the terms of service and the privacy notice.
How to use GPTinf
A typical end-to-end flow, from setup to results.
- Open gptinf.com in a browser; no installation and no account are needed to start.
- Pick the tool you need from the top navigation: detector, humanizer, paraphraser, plagiarism, readability or grammar.
- Paste your text into the editor, or upload it as a PDF, Word or plain-text file.
- For the detector, submit at least 30 words for reliable accuracy; there is no upper limit.
- Read the detection report: each sentence is labelled AI, Mixed or Human, with a per-model breakdown.
- Switch to the humanizer and choose your register, Standard or Academic.
- Lock any names, citations or brand terms you want preserved using Freeze Keywords.
- Click Humanize and let the engine restructure the text at sentence level.
- Check the detection score shown under the output, and re-run the whole text or just a selected passage if needed.
- Create a free account (email or Google sign-in) to unlock a further 120 humanized words, or subscribe for higher quotas.
Pros & Cons
Pros
- The AI detector is genuinely free and unlimited, with no sign-up, no paywall and no word cap.
- Six tools sit behind a single subscription instead of six separate ones.
- Every humanized output returns a detection score automatically, which keeps the check-and-fix loop short.
- Results are granular: a label and a stated reason for each sentence, plus a percentage match per generating model.
- Freeze Keywords protects citations and brand terms that a blind rewrite would otherwise mangle.
- The entry price is low at 4.99 USD per month on an annual term, and the interface is localised into nine languages.
- Cancellation is self-service and a refund can be requested within three days of payment.
Cons
- No API, no mobile app and no browser extension: the web app is the whole product.
- Pricing defaults to the annual term while still labelled "/monthly", so 4.99 USD is easy to misread as the month-to-month rate; the true monthly price is not rendered on the page.
- The site contradicts itself on retention: the homepage says text is not stored after the session, while the pricing FAQ describes an encrypted copy kept in a History dashboard.
- The homepage advertises eight writing modes but the humanizer page documents only two, Standard and Academic.
- The privacy notice and terms are both dated 21 February 2023 and were never updated after the May 2025 rebrand; the Termly template still reads "All payment data is stored by __________".
- No DPA, no Article 27 GDPR representative, no data protection officer and no security certification, while targeted advertising is listed among the processing purposes.
- A single obfuscated address, support@gptinf.com, serves as the legal, GDPR and support contact, and the refund window is only three days.
Pricing & Plans
A permanent free tier is available and requires no account: the AI detector, plagiarism, grammar and readability checks are advertised as unlimited, while the humanizer allows 120 words without registration and a further 120 once a free account is created. The lowest paid entry point is the Lite plan at 4.99 USD per month. Prospective buyers should note that the pricing page opens with the annual term pre-selected and a "Save 50%" banner, so that figure is a monthly equivalent billed yearly; the month-to-month rate is not published on the page. All payments are taken in US dollars and processed through Paddle, with Visa, Mastercard, American Express, Discover and PayPal accepted.
- no account required
- 120 humanized words without signing up and 240 in total with a free account
- AI detector
- plagiarism
- grammar and readability checks advertised as unlimited
- 4.99 USD/month billed annually
- 5
- 000 humanizer words and 2
- 500 paraphraser words
- 12.49 USD/month billed annually
- 25
- 000 humanizer words
- 12
- 500 paraphraser words and priority email support (flagged Most popular)
- 29.99 USD/month billed annually
- unlimited humanizer and paraphraser words
- top-tier support and first access to new features
Data, GDPR & hosting
A consolidated view of how GPTinf handles your data.
GDPR overview
GDPR is addressed concretely rather than merely name-checked. The privacy notice carries a dedicated section for EU and UK users that enumerates the legal bases relied on: consent, performance of a contract, legitimate interests, legal obligations and vital interests. A further section grants access, rectification, erasure, restriction, portability and objection rights, points EEA and UK users to their national supervisory authority, and routes requests through a Termly form or support@gptinf.com. What is missing matters too: no Article 27 representative is designated even though the controller is established outside the EU, no DPA is published, no data protection officer is named, and Do-Not-Track signals are expressly not honoured. The notice is dated 21 February 2023 and has not been revised since.
Who owns the data?
The terms of service state that GPTinf claims no ownership over your Contributions and that you retain full ownership of them and of the intellectual property rights attached. That ownership is qualified, however, by the licence you grant in the same document: an irrevocable, perpetual, transferable, worldwide and royalty-free right to host, use, copy and reproduce your content. A separate clause treats Submissions (feedback and ideas sent to the vendor) differently: those become the vendor's property outright. The pricing FAQ adds that an encrypted copy of your text is kept in your personal History dashboard, and the privacy notice lists "any inputs on the website" among the personal data collected.
Reuse rights
Nothing in the terms restricts what you may do with the text GPTinf returns to you: you keep ownership of your Contributions and no permission step, attribution requirement or commercial restriction is imposed on reusing the output. The constraints run the other way. You may not systematically retrieve content from the service to build a compilation or database without written permission, you may not use scripts, robots or data-mining tools against it, and the vendor reserves the right to throttle or suspend accounts it judges to be making excessive use. The service may not be used for commercial endeavours other than those the vendor specifically endorses, a clause that sits awkwardly beside the marketing-copy and SEO use cases the site itself promotes. Feedback and ideas you send become the vendor's property.
Data retention & training
Hosting summary
GPTinf states plainly in section 8 of its privacy notice that its servers are located in the United States, and that information from users elsewhere may be transferred to, stored and processed there and in other countries. The same section warns EEA and UK residents that these jurisdictions may not have data protection laws as comprehensive as their own, and commits only to taking necessary measures in line with the notice and applicable law. No transfer safeguard is named: neither Standard Contractual Clauses nor the EU-US Data Privacy Framework is mentioned, and no EU or regional hosting option is offered. The site is served through Cloudflare, so a DNS lookup resolves to an anycast CDN node rather than to the origin, and static assets are delivered from Vercel blob storage - neither tells you where the data actually rests. The governing law of the contract is Ukrainian, with exclusive jurisdiction in Ukrainian courts, which is a separate question from where the servers sit.
Things to keep in mind
Risks and trade-offs to weigh before adopting GPTinf.
- Academic integrity: the tool is sold on getting past AI detectors, and although GPTinf discourages cheating in writing, using it on graded work may breach your institution's rules and carry real consequences.
- Skill atrophy: routinely outsourcing rewriting and grading yourself against a detector score trains you to satisfy a classifier rather than to write better, and the judgement you skip is the judgement you stop developing.
- Misplaced confidence: the pricing page guarantees that all detectors are bypassed while the responsible-use page admits nothing is 100% undetectable - betting a submission on the stronger claim is a real risk.
- False accusations run the other way too: detection scores are probabilistic, non-native and heavily edited writing produce more false positives, and a grader treating a score as a verdict can harm an innocent student.
- Billing surprise: the pricing page defaults to annual terms shown as "/monthly", so a subscriber may commit to a year expecting a monthly charge, with only a three-day refund window to reverse it.
- Data ownership and retention: you keep ownership of your text but grant a perpetual worldwide licence over it, feedback you send becomes the vendor's property, and the site contradicts itself on whether your drafts are stored.
- Privacy exposure: drafts may contain unpublished, confidential or personal material, and it is sent to US servers under a policy that lists targeted advertising among its purposes and names no GDPR representative.
Setup & Integrations
Technical difficulty
Essentially none. GPTinf is a web application: there is nothing to install, no API key to obtain and no deployment step. The free tier can be used without even creating an account - open the relevant tool page, paste your text or upload a PDF, Word or plain-text file, pick a register and run it. Creating a free account takes a moment and can be done through Google sign-in. Anyone comfortable with a word processor will be productive within a minute or two.
Deployment
Integrations
Supported languages
Behind GPTinf
Social
Resources
All the official URLs gathered for verification and reference.
Frequently asked questions
What is GPTinf?
Is GPTinf free to use?
How much does the cheapest paid plan cost?
Does GPTinf train its models on my text?
Is there an API or a mobile app?
Where is my data hosted?
Who is behind GPTinf and where is the company based?
Is there a minimum age to use GPTinf?
Can I get a refund?
Will humanized text always pass an AI detector?
Should you pick GPTinf?
GPTinf packs a lot into a modest price. Six writing tools share one subscription, and the AI detector is unusually generous for a free tier: no account, no paywall, no word cap, with sentence-level labels and a per-model breakdown that most rivals reserve for paying users. The humanizer is the paid draw, and the design decisions around it are sensible - Freeze Keywords to protect citations, a detection score returned with every rewrite, selective re-runs on a single passage.
The weak point is not the product but the paperwork around it. The privacy notice and terms are Termly templates dated February 2023, never refreshed after the May 2025 rebrand, and one of them still carries an unfilled blank where the payment processor should be named. There is no DPA, no Article 27 representative despite the vendor sitting outside the EU, and targeted advertising appears among the stated processing purposes. Servers are in the United States with no regional alternative. For an individual writer none of this is disqualifying; for an institution or an employer it very likely is.
Two claims deserve a sceptical eye. The pricing page shows annual rates under a "/monthly" label, so the advertised 4.99 USD is not the month-to-month price. And the same page guarantees that its output bypasses all AI detectors, which the vendor's own responsible-use page contradicts. GPTinf is worth trying, and the free detector costs nothing to evaluate - but read the pricing toggle before you subscribe, and check your institution's rules before you rely on the humanizer.
- Choosing a selection results in a full page refresh.
- Opens in a new window.