{
    "title": "GPTZero Alternatives 2027: 14 Paid, Free & Open-Source",
    "url": "https://zekaiwork.com/alternatives/gptzero/",
    "summary": "The best GPTZero alternatives in 2027 are Originality.ai (best overall, $12.95/mo billed yearly), Scribbr (best free plan: Unlimited free AI checks) and SlopTotal (best open source, MIT). GPTZero itself starts at $12.99/mo billed yearly. Zekai checked these prices on vendor pages on 13 Nov 2026; 11 more are compared below, including 5 with a free plan and 4 open source.",
    "tool": {
        "name": "GPTZero",
        "starting_price": "$12.99/mo billed yearly",
        "free_plan": "10,000 words a month, 1 advanced scan",
        "price_checked": "2026-11-12",
        "pricing_url": "https://gptzero.me/pricing"
    },
    "task": "AI content detector",
    "prices_checked": "2026-11-13",
    "date_modified": "2026-11-13",
    "alternatives": [
        {
            "name": "Copyleaks",
            "type": "Free plan + paid",
            "starting_price": "$13.99/mo billed yearly",
            "free_plan_limit": "25,000 characters per free scan; no free plan on pricing page",
            "best_for": "Plagiarism plus AI checks bought by credit",
            "difference": "Sells by credit: Personal gives 100 credits a month, one credit covering up to 250 words or 1 image; Pro adds 25 seats and website scanning by sitemap, which GPTZero's page does not list.",
            "price_checked": "2026-11-12",
            "pricing_url": "https://copyleaks.com/pricing",
            "website": "https://copyleaks.com",
            "zekai_score": 6.6,
            "zekai_review": "https://zekaiwork.com/ai-tools/copyleaks/"
        },
        {
            "name": "Originality.ai",
            "type": "Free plan + paid",
            "starting_price": "$12.95/mo billed yearly",
            "free_plan_limit": "10K words (100 credits) one time; comparison table says 60 credits renewing daily",
            "best_for": "Bulk content checks for publishers and agencies",
            "difference": "Pro gives 200K words (2K credits) a month with 30-day scan history, bulk scan, PDF download and paid extra seats at $8.62 a month; GPTZero Premium gives 300,000 words but no extra team seats.",
            "price_checked": "2026-11-12",
            "pricing_url": "https://originality.ai/pricing",
            "website": "https://originality.ai",
            "zekai_score": 7.7,
            "zekai_review": "https://zekaiwork.com/ai-tools/originality-ai/"
        },
        {
            "name": "Winston AI",
            "type": "Free plan + paid",
            "starting_price": "$10/mo billed yearly",
            "free_plan_limit": "2,000 credits, 14-day trial",
            "best_for": "Detecting AI text, images and deepfakes together",
            "difference": "Credit-based: Essential gives 100,000 credits a month and covers AI image and deepfake detection, OCR for scans and handwriting, plagiarism checks and shareable PDF reports; Advanced adds 5 team members.",
            "price_checked": "2026-11-12",
            "pricing_url": "https://gowinston.ai/pricing/",
            "website": "https://gowinston.ai",
            "zekai_score": 7.7,
            "zekai_review": "https://zekaiwork.com/ai-tools/winston-ai/"
        },
        {
            "name": "ZeroGPT",
            "type": "Free plan + paid",
            "starting_price": "$8.99/mo billed yearly",
            "free_plan_limit": "15,000 characters per AI detection",
            "best_for": "Quick free AI text checks with batch upload",
            "difference": "Free forever at $0 with 15,000 characters per detection; Pro lifts it to 100,000 characters and 50 batch files and adds an AI video detector, summarizer and a WhatsApp or Telegram bot.",
            "price_checked": "2026-11-12",
            "pricing_url": "https://www.zerogpt.com/pricing",
            "website": "https://www.zerogpt.com",
            "zekai_score": 4.6,
            "zekai_review": "https://zekaiwork.com/ai-tools/zerogpt/"
        },
        {
            "name": "Quetext",
            "type": "Free plan + paid",
            "starting_price": "$14.99/mo",
            "free_plan_limit": "AI detector up to 1,000 words; plagiarism checker up to 1,000 words",
            "best_for": "Plagiarism checker and AI detector bundle",
            "difference": "Essential bundles a plagiarism checker and AI detector on 100k words a month, plus a humanizer, summarizer, API access and 20-file bulk upload; the free AI detector stops at 1,000 words.",
            "price_checked": "2026-11-12",
            "pricing_url": "https://www.quetext.com/pricing",
            "website": "https://www.quetext.com",
            "zekai_score": 7.6,
            "zekai_review": "https://zekaiwork.com/ai-tools/quetext/"
        },
        {
            "name": "Isgen",
            "type": "Paid",
            "starting_price": "$8/mo billed yearly",
            "free_plan_limit": "No free plan",
            "best_for": "Low-cost academic detector with plagiarism check",
            "difference": "Academic plan is $8 a month billed yearly ($14 monthly) for 350,000 detection words a month, phrase-level analysis, a plagiarism checker, 60,000 characters per submission and 15 days of history.",
            "price_checked": "2026-11-12",
            "pricing_url": "https://isgen.ai/pricing",
            "website": "https://isgen.ai",
            "zekai_score": 7.3,
            "zekai_review": "https://zekaiwork.com/ai-tools/isgen/"
        },
        {
            "name": "Sapling",
            "type": "Free plan + paid",
            "starting_price": "$25/mo",
            "free_plan_limit": "2,000 characters per check, 5 files per batch",
            "best_for": "AI detector inside a writing-suggestions tool",
            "difference": "Free detector checks stop at 2,000 characters; Pro raises that to 100,000 characters and 10 files per batch and adds writing suggestions plus a usage-billed API ($5 minimum).",
            "price_checked": "2026-11-12",
            "pricing_url": "https://sapling.ai/pricing",
            "website": "https://sapling.ai",
            "zekai_score": 7.5,
            "zekai_review": "https://zekaiwork.com/ai-tools/sapling/"
        },
        {
            "name": "Scribbr",
            "type": "Free",
            "starting_price": "Free plan; paid price not published",
            "free_plan_limit": "Unlimited free AI checks, no sign-up; word cap not stated",
            "best_for": "Students wanting a no-sign-up free check",
            "difference": "Advertises unlimited free AI checks with no sign-up and a separate Premium AI Detector; the page states no word cap and no published Premium price.",
            "price_checked": "2026-11-12",
            "pricing_url": "https://www.scribbr.com/ai-detector/",
            "website": "https://www.scribbr.com",
            "zekai_score": 7.5,
            "zekai_review": "https://zekaiwork.com/ai-tools/scribbr/"
        },
        {
            "name": "Turnitin",
            "type": "Paid",
            "starting_price": "Not checked",
            "free_plan_limit": "No free plan",
            "best_for": "Institution-wide similarity and AI writing checks",
            "difference": "Sold to institutions through sales with LMS integration; its AI writing detection is described as available with Originality, and no price or free tier is published.",
            "price_checked": "2026-11-12",
            "pricing_url": "https://turnitin.com/solutions/ai-writing",
            "website": "https://www.turnitin.com",
            "zekai_score": 8.6,
            "zekai_review": "https://zekaiwork.com/ai-tools/turnitin/"
        },
        {
            "name": "SlopTotal",
            "type": "Open source",
            "starting_price": "Free (self-hosted)",
            "free_plan_limit": "No limit (self-hosted)",
            "licence": "MIT",
            "best_for": "Self-hosted multi-engine AI text detector",
            "difference": "Runs 23 detection engines, including Binoculars and Fast-DetectGPT, on your own CPU and returns one calibrated score with per-engine votes, file and URL scanning, and a JSON API.",
            "price_checked": "2026-11-13",
            "website": "https://sloptotal.com",
            "repository": "https://github.com/pablocaeg/sloptotal",
            "zekai_open_source_page": "https://zekaiwork.com/free-open-source/sloptotal/",
            "commercial_use": "Yes (MIT).",
            "runs_on": "Runs on CPU; loaded models need about 8.3 GB of RAM; GPU optional.",
            "setup": "moderate: One docker run command; models download on first start.",
            "github_stars": 114,
            "stars_checked": "2026-11-13",
            "last_commit": "2026-11-03",
            "last_release": "2026-11-03",
            "zekai_score": 6.9,
            "zekai_review": "https://zekaiwork.com/free-open-source/sloptotal/"
        },
        {
            "name": "Binoculars",
            "type": "Open source",
            "starting_price": "Free (self-hosted)",
            "free_plan_limit": "No limit (self-hosted)",
            "licence": "BSD-3-Clause",
            "best_for": "Research-grade zero-shot detection you run yourself",
            "difference": "Zero-shot detector needing no training data; it scores text with two Falcon-7B models locally and returns a score, without sentence highlighting or a web dashboard.",
            "price_checked": "2026-11-13",
            "website": "https://github.com/ahans30/Binoculars",
            "repository": "https://github.com/ahans30/Binoculars",
            "zekai_open_source_page": "https://zekaiwork.com/free-open-source/binoculars/",
            "commercial_use": "Yes for the code (BSD-3-Clause); check the licence of the Falcon models you download.",
            "runs_on": "Python 3.9; two 7B models, so a GPU or large-memory machine.",
            "setup": "hard: Clone the repo, pip install, then download two 7B models.",
            "github_stars": 435,
            "stars_checked": "2026-11-13",
            "last_commit": "2024-05-14",
            "zekai_score": 3.5,
            "zekai_review": "https://zekaiwork.com/free-open-source/binoculars/"
        },
        {
            "name": "Fast-DetectGPT",
            "type": "Open source",
            "starting_price": "Free (self-hosted)",
            "free_plan_limit": "No limit (self-hosted)",
            "licence": "MIT",
            "best_for": "Zero-shot detection from an ICLR 2024 paper",
            "difference": "ICLR 2024 zero-shot method using conditional probability curvature; the README reports 0.9887 AUROC on five-model generations and ships a local script, with no dashboard or upload.",
            "price_checked": "2026-11-13",
            "website": "https://fastdetect.net/",
            "repository": "https://github.com/baoguangsheng/fast-detect-gpt",
            "zekai_open_source_page": "https://zekaiwork.com/free-open-source/fast-detect-gpt/",
            "commercial_use": "Yes (MIT).",
            "runs_on": "Authors ran it on an 80 GB A100; the local demo defaults to gpt-neo-2.7B.",
            "setup": "hard: Python 3.8 and PyTorch 1.10 environment plus model downloads.",
            "github_stars": 440,
            "stars_checked": "2026-11-13",
            "last_commit": "2026-02-07",
            "zekai_score": 5.1,
            "zekai_review": "https://zekaiwork.com/free-open-source/fast-detect-gpt/"
        },
        {
            "name": "Open Detector",
            "type": "Open source",
            "starting_price": "Free (self-hosted)",
            "free_plan_limit": "No limit (self-hosted)",
            "licence": "MIT",
            "best_for": "Academic-paper AI detection with a small model",
            "difference": "BERT-base classifier trained for academic papers; the README claims 99.57% accuracy on its own dataset and says it is stylometric only. It is a model and script, not a web app.",
            "price_checked": "2026-11-13",
            "website": "https://github.com/Imalwayshere/Open-Detector",
            "repository": "https://github.com/Imalwayshere/Open-Detector",
            "zekai_open_source_page": "https://zekaiwork.com/free-open-source/open-detector/",
            "commercial_use": "Yes (MIT); the Hugging Face model card also states MIT.",
            "runs_on": "Python with PyTorch and Transformers; BERT-base model, 512-token input.",
            "setup": "moderate: pip install transformers torch, then a short Python script.",
            "github_stars": 254,
            "stars_checked": "2026-11-13",
            "last_commit": "2026-11-12",
            "zekai_score": 6.4,
            "zekai_review": "https://zekaiwork.com/free-open-source/open-detector/"
        },
        {
            "name": "SynthID Text",
            "type": "Open source",
            "starting_price": "Free (self-hosted)",
            "free_plan_limit": "No limit (self-hosted)",
            "licence": "Apache-2.0",
            "best_for": "Watermark detection for text you generate",
            "difference": "Google DeepMind reference code that detects only text carrying its SynthID watermark; the frequentist detector gives a binomial p-value for a key, so it cannot flag unwatermarked ChatGPT or Claude output.",
            "price_checked": "2026-11-13",
            "website": "https://github.com/google-deepmind/synthid-text",
            "repository": "https://github.com/google-deepmind/synthid-text",
            "zekai_open_source_page": "https://zekaiwork.com/free-open-source/synthid-text/",
            "commercial_use": "Yes (Apache-2.0), but the repo calls itself a reference implementation, not for production.",
            "runs_on": "Any GPU such as a T4 for Gemma 3 270M; GPT-2 runs on CPU.",
            "setup": "moderate: Python virtual environment and a Jupyter notebook from the repo.",
            "github_stars": 1300,
            "stars_checked": "2026-11-13",
            "last_commit": "2026-10-26",
            "zekai_score": 6.3,
            "zekai_review": "https://zekaiwork.com/free-open-source/synthid-text/"
        }
    ],
    "faq": [
        {
            "q": "What is the best alternative to GPTZero in 2027?",
            "a": "Originality.ai is the best overall GPTZero alternative on this page ($12.95/mo billed yearly). For no cost, Scribbr has a free plan (Unlimited free AI checks, no sign-up; word cap not stated). To self-host, SlopTotal is open source (MIT)."
        },
        {
            "q": "Is there a free version of GPTZero?",
            "a": "Yes. GPTZero has a free plan: 10,000 words a month, 1 advanced scan. Paid plans start at $12.99/mo billed yearly, checked on 12 Nov 2026."
        },
        {
            "q": "Is there a 100% free alternative to GPTZero?",
            "a": "Yes. SlopTotal, Binoculars, Fast-DetectGPT, Open Detector, SynthID Text are open source and free to self-host. Copyleaks, Originality.ai, Winston AI, ZeroGPT, Quetext, Sapling, Scribbr have a free plan with limits, shown in the table."
        },
        {
            "q": "What is cheaper than GPTZero?",
            "a": "Isgen starts at $8/mo billed yearly, against $12.99/mo billed yearly for GPTZero, as listed on each vendor's pricing page on 12 Nov 2026."
        },
        {
            "q": "How much do GPTZero alternatives cost for a team of 5?",
            "a": "If each of 5 people buys the entry paid plan, at the prices Zekai checked on 13 Nov 2026, the monthly cost is Isgen $40/mo, ZeroGPT $44.95/mo, Winston AI $50/mo, against GPTZero $64.95/mo for GPTZero. Team and business plans can cost more per seat. The Zekai Cost Finder on this page recalculates for any team size."
        },
        {
            "q": "Which is better, Originality.ai or GPTZero?",
            "a": "Pro gives 200K words (2K credits) a month with 30-day scan history, bulk scan, PDF download and paid extra seats at $8.62 a month; GPTZero Premium gives 300,000 words but no extra team seats. Choose Originality.ai if you vet freelancer or agency articles in bulk and want scan history, shareable reports and add-on seats. Stay with GPTZero if you check single essays and want a free quota that resets monthly instead of a one-time allowance."
        },
        {
            "q": "Why are people leaving GPTZero?",
            "a": "The documented reasons are: Premium costs $23.99 a month billed monthly versus $12.99 a month billed annually, and Professional is $45.99 monthly versus $24.99 annually; the page advertises a 45% annual saving (12 Nov 2026); The Free plan is capped at 10,000 words a month with 1 advanced scan; Premium raises that to 300,000 words a month and 50,000 characters per scan, and plagiarism checking and page-by-page scanning sit only in higher tiers (12 Nov 2026). Each is sourced in the section above."
        },
        {
            "q": "What is better than GPTZero?",
            "a": "It depends on the job: Originality.ai for bulk publisher checks, Winston AI for images and deepfakes, Copyleaks for credit-based plagiarism checks, Turnitin for institutions."
        }
    ],
    "publisher": "Zekai (zekaiwork.com) — independently reviewed; prices read on vendor pages on the dates shown.",
    "licence": "Free to quote with a link to https://zekaiwork.com/alternatives/gptzero/. Bulk copying or republishing the dataset is not permitted."
}