10 Best AI Detectors of 2026

GPTZero is built around the classroom: it scans text from ChatGPT, Gemini, Claude and Llama, highlights sentences that look AI-written, and flags text that was paraphrased or run through a bypass tool. The free plan gives 10,000 words a month, which covers a handful of essays, and the Chrome extension adds AI highlights in Gmail, Google Docs and Google Classroom. Premium costs $12.99 a month on annual billing for 300,000 words, multilingual detection and downloadable reports. Professional at $24.99 adds batch uploads of 250 files, page by page scanning and LMS integration with Canvas and Google Classroom. Writing Replay is the feature teachers ask about most: it replays how a Google Doc was written, including pastes. The trade-offs are that LMS links require the higher plan and the 99.9 percent accuracy figure is a vendor claim. We compared documented features and published prices.

Pangram targets people who judge writing for a living: its site names professors, editors and researchers, and the Individual plan bundles text detection, image detection and similarity checks. For $20 a month after a 7-day free trial, you get 300,000 words, 100 image scans, file upload with OCR for scanned pages, and integrations with Google Docs and Gmail. A browser extension can scan feeds on social media and Substack, and the plan includes $10 of API credits each month. The Professional plan costs $65 a month with five times the words and image scans plus $200 of API credits, which suits small editorial teams. API pricing is published openly at $0.05 per 100 words of text. The main drawback for teachers is the lack of a permanent free plan and the higher entry price compared with GPTZero or Originality.ai. We compared documented features and published prices.

Originality.ai is aimed at publishers and agencies that buy content and want proof it was written by a person. Every plan uses credits worth 100 words, and Pro gives 2,000 credits, or 200,000 words, each month for $12.95 on annual billing or $14.95 monthly. The same credits run an AI checker, plagiarism checker, fact and hallucination checker, readability score and a guideline checker, so an editor can run one report on a freelance draft. Pro adds bulk scans, file uploads, shareable reports and team management, and extensions cover Chrome, Google Docs and Firefox. Schools can use the Moodle plugin. The free tier is limited to a one-time 10,000 words, Pro keeps 30 days of history, and API access only arrives with Enterprise at $136.58 a month billed annually. We compared documented features and published prices.

Copyleaks combines AI detection and plagiarism matching in a single report, which saves teachers and editors from running two tools on the same document. The Personal plan costs $13.99 a month billed annually and includes 1,200 unified credits, enough for up to 300,000 words or 1,200 images. Copyleaks lists AI detection in more than 30 languages and plagiarism detection in more than 100, plus multi-file uploads, a browser extension, a Google Docs add-on and MCP access. The Pro plan at $74.99 a month adds 25 user seats, website scans, cross-language translation detection and an analytics dashboard, which suits small departments. Separate Education and Enterprise plans are sold through the same pricing page. Drawbacks: there is no permanent free plan shown, and image and text scans draw from the same credits. We compared documented features and published prices.

Winston AI pairs text detection for ChatGPT, Gemini and Claude with AI image and deepfake detection, and its OCR reads photographed pages and handwriting, which helps teachers who still collect paper work. The Essential plan lists $18 a month on monthly billing or $10 a month on annual billing, and includes 100,000 credits a month, writing feedback, document and image scans, shareable PDF reports and advanced plagiarism detection. The pricing page also advertises 50 percent off with code WINSTON50. Winston adds education tools such as an essay grader and citation generator, and a website certification called HUMN-1 for publishers. The free option is a 14-day trial with 2,000 credits, not a permanent plan, and the credit system takes more effort to compare against word-based plans. We compared documented features and published prices.

Grammarly's AI Detector is a free web tool that shows what share of a text appears AI-generated, and the paid Pro plan lists detection of plagiarism and AI generated text next to its rewriting features. It identifies text from Grammarly itself and from tools like ChatGPT, Gemini and Claude, explains why a phrase may be flagged, and offers one-click rewrites. Grammarly says the detector achieves 99 percent accuracy and ranks first on the RAID benchmark; those are vendor claims we did not test. The strength is convenience for writers and editors who already use Grammarly in Google Docs, Microsoft Office or the browser. The weakness for teachers is the lack of class tools: there are no batch scans, LMS links or shareable class reports on the plans page. The Pro price showed in EUR from our location, so the USD price is pending. We compared documented features and published prices.

Turnitin is the AI detector many students meet without choosing it: institutions that license Turnitin Originality get an AI writing indicator inside the Similarity Report, visible only to instructors and administrators. The indicator gives the share of sentences the model labels as AI and links to highlighted segments, including text that was changed by paraphraser or humanizer tools. Turnitin publishes its limits openly: files need at least 300 words of prose and no more than 30,000, scores below 20 percent are hidden, and the company targets a false positive rate under 1 percent for documents with over 20 percent AI writing. It supports long-form English, Spanish, Japanese, Arabic, Dutch and German. Turnitin says the score should not be the sole basis for action. The catch is access: there is no self-serve plan or public price, so individual teachers, editors and publishers outside a licensed institution cannot buy it. We compared documented features and published prices.

Sapling sells AI detection alongside a writing assistant, and its pricing is easy to read. The free plan checks up to 2,000 characters at a time, roughly a short page, with batches of 5 files. Pro costs $12 a month on annual billing or $25 monthly and raises each check to 100,000 characters with batches of 10 files, plus advanced writing suggestions and email support. New accounts get a free 1-month Pro trial. Developers can use a separate metered API with a one-time $5 minimum and up to 200,000 characters per request, returning JSON; Sapling says Pro and the API use the same default detector model. Enterprise starts at 10 seats for $15 per seat per month with SSO and team analytics. For teachers, the free character limit is tight and there is no LMS integration. We compared documented features and published prices.

ZeroGPT has the lowest paid entry price in this list. The free plan needs no credit card and checks up to 15,000 characters at a time. Pro costs $8.99 a month on annual billing, $107.88 a year, or $14.99 monthly, and raises each check to 100,000 characters with batches of 50 files, PDF reports, detection history and an ad-free experience. Plus at $13.99 and Max at $19.99 add monthly plagiarism allowances of 35,000 and 60,000 words, and Business and EDU plans are sold on the same page. Paid plans also include a summarizer, paraphraser, grammar checker, chat assistant and a humanizer, so ZeroGPT is as much a writing toolkit as a detector. For editors that bundle matters less than the detector's limits, and Pro includes only a one-time 750 words of plagiarism checking. We compared documented features and published prices.

Scribbr's AI Detector is free, unlimited and needs no account, which makes it the easiest tool here for a quick check. Each submission can be up to 1,200 words, and results separate human-written, AI-generated and AI-refined text, with paragraph-level feedback on which passages look AI-written or AI-polished. It supports English, German, French and Spanish, and Scribbr says submissions are not stored or shared. Scribbr is best known for proofreading and plagiarism checks aimed at students, and the detector is positioned for students checking their own papers, educators and bloggers. The limits are clear: no batch uploads, no downloadable reports and no class tools, and the page itself suggests QuillBot's detector for more advanced checks. Teachers handling whole classes should look at GPTZero or Turnitin instead. We compared documented features and published prices.