{ "title": "Copyleaks Alternatives 2027: 16 Paid, Free & Open-Source", "url": "https://zekaiwork.com/alternatives/copyleaks/", "summary": "The best Copyleaks alternatives in 2027 are Originality.ai (best overall, $12.95/mo billed yearly), GPTZero (best free plan: 10,000 words a month) and SlopTotal (best open source, MIT). Copyleaks itself starts at $13.99/mo billed yearly. Zekai checked these prices on vendor pages on 13 Nov 2026; 13 more are compared below, including 4 with a free plan and 6 open source.", "tool": { "name": "Copyleaks", "starting_price": "$13.99/mo billed yearly", "free_plan": "25,000 characters per free scan; no free plan on pricing page", "price_checked": "2026-11-12", "pricing_url": "https://copyleaks.com/pricing" }, "task": "AI content detector", "prices_checked": "2026-11-13", "date_modified": "2026-11-13", "alternatives": [ { "name": "GPTZero", "type": "Free plan + paid", "starting_price": "$12.99/mo billed yearly", "free_plan_limit": "10,000 words a month, 1 advanced scan", "best_for": "Teachers wanting sentence highlights and model detection", "difference": "Free plan allows 10,000 words a month; Premium lists 300,000 words a month, multi-model detection (Gemini, Claude, LLaMa), 50,000 characters per scan and 50-file batch upload, billed per word not per credit.", "price_checked": "2026-11-12", "pricing_url": "https://gptzero.me/pricing", "website": "https://gptzero.me", "zekai_score": 6.3, "zekai_review": "https://zekaiwork.com/ai-tools/gptzero/" }, { "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, shareable reports and a Chrome extension; Copyleaks Personal gives 100 credits of 250 words each, about 25,000 words.", "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 with 15,000 characters per detection and no card; Pro at $8.99 a month billed yearly allows 100,000 characters, 50 batch files and a 750-word one-time plagiarism check.", "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": "PlagiarismCheck.org", "type": "Paid", "starting_price": "Not checked", "free_plan_limit": "No free plan", "best_for": "Institutional plagiarism and AI checks", "difference": "Sells Advanced and Pro organisation plans by quote only; the pricing page lists a Google Docs add-on, LMS integrations and onboarding, and Pro offers any interface language.", "price_checked": "2026-11-12", "pricing_url": "https://plagiarismcheck.org/pricing/", "website": "https://plagiarismcheck.org", "zekai_score": 5.5, "zekai_review": "https://zekaiwork.com/ai-tools/plagiarismcheckorg/" }, { "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/" }, { "name": "Dolos", "type": "Open source", "starting_price": "Free (self-hosted)", "free_plan_limit": "No limit (self-hosted)", "licence": "MIT", "best_for": "Source-code plagiarism checks in programming courses", "difference": "Compares source-code submissions with each other and shows similarity scores and a side-by-side view; it checks code only and does not detect AI-written prose.", "price_checked": "2026-11-13", "website": "https://dolos.ugent.be", "repository": "https://github.com/dodona-edu/dolos", "zekai_open_source_page": "https://zekaiwork.com/free-open-source/dolos/", "commercial_use": "Yes (MIT).", "runs_on": "Node.js 22 or newer, or Docker; a free hosted web app also exists.", "setup": "easy: npm install -g @dodona/dolos gives a CLI; web hosting needs Docker.", "github_stars": 357, "stars_checked": "2026-11-13", "last_commit": "2026-11-12", "last_release": "2026-10-19", "zekai_score": 7.1, "zekai_review": "https://zekaiwork.com/free-open-source/dolos/" }, { "name": "JPlag", "type": "Open source", "starting_price": "Free (self-hosted)", "free_plan_limit": "No limit (self-hosted)", "licence": "GPL-3.0", "best_for": "Source-code plagiarism checks across many languages", "difference": "Finds pairwise similarities among a set of programs and shows them in a report viewer; it compares source code in many languages and does not read essays or detect AI-written prose.", "price_checked": "2026-11-13", "website": "https://github.com/jplag/JPlag", "repository": "https://github.com/jplag/JPlag", "zekai_open_source_page": "https://zekaiwork.com/free-open-source/jplag/", "commercial_use": "Yes; GPL-3.0 means sharing source if you distribute changes.", "runs_on": "Java SE 25; runs locally, and no code or results are uploaded.", "setup": "moderate: Download a release jar and run it on Java 25.", "github_stars": 2000, "stars_checked": "2026-11-13", "last_commit": "2026-10-05", "last_release": "2025-12-11", "zekai_score": 7.3, "zekai_review": "https://zekaiwork.com/free-open-source/jplag/" } ], "faq": [ { "q": "What is the best alternative to Copyleaks in 2027?", "a": "Originality.ai is the best overall Copyleaks alternative on this page ($12.95/mo billed yearly). For no cost, GPTZero has a free plan (10,000 words a month, 1 advanced scan). To self-host, SlopTotal is open source (MIT)." }, { "q": "Is there a free version of Copyleaks?", "a": "Yes. Copyleaks has a free plan: 25,000 characters per free scan; no free plan on pricing page. Paid plans start at $13.99/mo billed yearly, checked on 12 Nov 2026." }, { "q": "Is there a 100% free alternative to Copyleaks?", "a": "Yes. SlopTotal, Binoculars, Fast-DetectGPT, Open Detector, SynthID Text, Dolos, JPlag are open source and free to self-host. GPTZero, Originality.ai, Winston AI, ZeroGPT, Quetext, Scribbr have a free plan with limits, shown in the table." }, { "q": "What is cheaper than Copyleaks?", "a": "Isgen starts at $8/mo billed yearly, against $13.99/mo billed yearly for Copyleaks, as listed on each vendor's pricing page on 12 Nov 2026." }, { "q": "How much do Copyleaks 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 Copyleaks $69.95/mo for Copyleaks. 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 Copyleaks?", "a": "Pro gives 200K words (2K credits) a month with 30-day scan history, bulk scan, shareable reports and a Chrome extension; Copyleaks Personal gives 100 credits of 250 words each, about 25,000 words. Choose Originality.ai if you audit freelance copy for a publisher and want 200K words a month with team seats and scan history. Stay with Copyleaks if you need plagiarism checks across 30 languages plus image detection from one credit pool." }, { "q": "Why are people leaving Copyleaks?", "a": "The documented reasons are: Personal costs $16.99 a month billed monthly versus $13.99 a month billed annually, and Pro $99.99 monthly versus $74.99 annually; the pricing page lists no free plan (12 Nov 2026); Personal includes 100 credits a month, with one credit covering up to 250 words or 1 image, which is roughly 25,000 words; Pro includes 1,000 credits and 25 seats, and the API is sold through sales for education and enterprise (12 Nov 2026). Each is sourced in the section above." }, { "q": "What is better than Copyleaks?", "a": "It depends on the job: GPTZero for sentence highlights and a monthly free quota, Turnitin for institutions, Originality.ai for bulk publisher checks, Winston AI for images." } ], "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/copyleaks/. Bulk copying or republishing the dataset is not permitted." }