GPTZero
GPTZero is an AI content detector built to preserve what is human, trusted by over 17 million users including one million educators. Paste text or upload files to detect writing from ChatGPT, GPT-5, Gemini, Claude, Llama, and DeepSeek with sentence-level highlights, multilingual scans, plagiarism checks, and free grammar and writing feedback. Used in more than 100 countries.
What is GPTZero?
GPTZero is an AI content detection platform whose mission is to preserve what is human, best known as the leading detector of machine-generated text in education and increasingly used in hiring, publishing, and business. Launched in January 2023, it has served tens of millions of users - the homepage cites 17 million, including more than one million educators - and is used in over 100 countries by organizations such as the New York Times, Stanford, Microsoft, and the American Federation of Teachers, which named GPTZero its official AI detector partner. The technology is a proprietary detection model with seven components that analyze text for the statistical fingerprints of machine writing, such as low perplexity (predictable wording), low burstiness (uniform sentence rhythm), and generic style, producing an overall AI probability plus color-coded, sentence-level highlights that explain exactly which phrases look AI-generated. Its claims are benchmarked: GPTZero says it classifies AI versus human writing with 99% accuracy overall, and on the third-party RAID benchmark it detected 95.7% of AI texts while misclassifying only 1% of human texts, with accuracy above 99% on modern models such as GPT-4 and a 96.5% success rate on mixed human-plus-AI documents. The detector covers ChatGPT, GPT-5, GPT-4, Gemini, Claude, Llama, DeepSeek, and services built on them, fully supports English, German, Portuguese, French, and Spanish, and is de-biased for ESL writers to keep false positives near one percent. Beyond detection, the platform has expanded into a full writing-integrity suite: an Advanced Scan for paraphrased or bypassed AI content, a plagiarism checker, grammar checking and AI-powered writing feedback with source finding and auto-generated citations, an AI tutor, a hallucination detector, and AI Vision for scanning handwritten work. Its free Chrome extension brings detection to Gmail, Google Docs, Google Classroom, Canvas, LinkedIn, and social media, while the Google Docs add-on records Writing Replay - video proof of the writing process showing copy-pastes and typing patterns - so authors can verify authentic work. Premium features add downloadable AI reports, multilingual detection, and AI highlights in the extension. For organizations, GPTZero integrates with learning management systems like Canvas and Google Classroom, offers team plans with shared credits and unified billing, enterprise roles and account provisioning, and a developer API with ready-to-use code in 17 languages including Node.js, Python, C#, Java, and PHP. In 2026 GPTZero announced it is now part of Superhuman. Pricing is freemium: free scans on the web, then Premium at $12.99 per month billed annually (300,000 words per month) and Professional at $24.99 per month (500,000 words plus overage), with limited-time 30% back-to-school discounts on annual plans.
GPTZero Core Features
Multi-model AI detection
Classify text from ChatGPT, GPT-5, Gemini, Claude, Llama, DeepSeek, and more in a single scan.
Sentence-level AI highlighting
See exactly which phrases look AI-generated with color-coded, explainable results.
Advanced Scan accuracy
Detect paraphrased, mixed, and bypassed AI content in longer documents with best-in-class benchmarks.
Multilingual detection
Scan English, German, Portuguese, French, and Spanish, de-biased for ESL writers.
Plagiarism checker
Verify originality and flag content copied from outside sources without attribution.
Writing feedback and grammar
Get free grammar checks, AI tutor feedback, and sources with auto-generated citations.
Writing Replay in Google Docs
Prove authorship with video of the writing process, copy-pastes, and typing patterns.
Chrome extension everywhere
Detect AI automatically across Gmail, Google Docs, Classroom, Canvas, and social media.
Who is GPTZero for?
GPTZero was founded in January 2023 for a simple audience: teachers who needed to know whether a student's essay was written by a machine. Today it is the most widely used AI checker in education, trusted by more than one million educators across over 3,500 colleges and hundreds of institutions, plus the American Federation of Teachers as official AI detector partner. Instructors use it to guide conversations about academic integrity rather than to punish, reviewing sentence-level highlights with students and pointing them toward writing support. Administrators use team and institutional plans to observe AI usage across campus, which informs policies on responsible AI adoption. Students use the free Chrome extension, Google Docs integration, and writing reports - including video replay of the writing process - to prove their work is authentically human and to improve drafts with grammar checks and citations. Beyond the classroom, recruiters and hiring managers verify that resumes, cover letters, and writing samples are genuinely human-authored, which matters in roles where communication quality is the job. Publishers, editors, and journalists screen submissions for undisclosed AI content and plagiarism before publication. Copywriters, marketers, and freelancers run their own drafts through the detector to confirm a human voice and to catch accidental AI-sounding passages. Legal, government, and enterprise teams use GPTZero's API, batch scanning, and enterprise-grade security to integrate AI detection into their own platforms and review pipelines. The tool supports English, German, Portuguese, French, and Spanish with full accuracy and is deliberately de-biased for ESL writers, reducing false positives on non-native English to about one percent, which makes it fairer for international students and global teams. Whatever the setting, GPTZero serves people who need a reliable, explainable second opinion on whether text was written by a human, by AI, or by a mix of both.
GPTZero Use Cases
Check student essays for AI-generated content before grading or academic-integrity reviews.
Verify that candidate resumes, cover letters, and writing samples are authentically human-written.
Screen multilingual submissions for AI content in English, German, French, Spanish, or Portuguese.
Prove authentic authorship with Writing Replay video of your own Google Docs process.
Audit manuscripts and submissions for AI-generated or plagiarized passages as an editor.
Scan batches of up to 250 files at once for institutional AI-usage reviews.
Integrate AI detection into your platform with the developer API in 17 languages.
Improve drafts by pairing AI highlights with grammar feedback and auto-generated citations.
GPTZero Pros and Cons
Pros
- Widely trusted and independently benchmarked, including a 99% accuracy claim and official American Federation of Teachers partnership.
- Explainable results with sentence-level highlights rather than a black-box score.
- Free entry point: web scans, Chrome extension, Google Docs add-on, grammar checks, and writing feedback.
- Multilingual support with ESL de-biasing that keeps false positives near 1% for non-native writers.
- Deep integrations for education and business, including Canvas, Google Classroom, and a 17-language API.
Cons
- No AI detector is 100% accurate, and GPTZero itself cautions that results should not be used as a final verdict or to punish students.
- Generous but capped word allowances (300,000 to 500,000 words per month) can require overage or team plans for heavy institutional use.
- The most powerful tools - Advanced Scan, plagiarism checks, batch scanning, and API access - sit behind paid Premium, Professional, or enterprise plans.
FAQ About GPTZero
GPTZero Pricing
GPTZero is freemium: free web scans, Chrome extension, and writing tools, then Premium at $12.99 per month (300,000 words) and Professional at $24.99 per month (500,000 words), both billed annually with limited-time 30% discounts, plus team and enterprise plans.
Check official pricingFree
Scan up to 10,000 characters without an account and more with a free account; includes the Chrome extension, Google Docs add-on, grammar check, and writing feedback.
Premium
300,000 words per month, Advanced AI Scan, multilingual detection, downloadable AI reports, and AI highlights in the Chrome extension.
Professional
500,000 words per month with up to 2 million words of overage, batch scanning of 250 files, page-by-page scanning, plagiarism checker, and LMS integration.
Team
Two Professional seats at $24.99 per member per month with shared team credits, unified billing, and a team admin dashboard; larger teams available.
GPTZero Alternatives
ZeroGPT
ZeroGPT is a free AI detector and writing suite. Paste text or upload files and its DeepAnalyse™ model scores the content for ChatGPT, GPT-5, Gemini, Grok, Claude, DeepSeek and Llama text, highlighting each flagged sentence and exporting PDF reports. Plagiarism checking, an AI humanizer, image and video detection, a paraphraser, summarizer, grammar checker, translator, word counter and citation generator sit alongside it. The API supports pay-as-you-go integration.
StealthGPT
StealthGPT rewrites AI-generated text into natural, human-sounding writing that bypasses AI detectors such as GPTZero, Turnitin, and Originality.ai. It includes an AI humanizer, a free AI detector, a stealth writer for essays and SEO content, a research agent, chat with PDF, and a Chrome extension, plus API, MCP, Zapier, and WordPress integrations.
Mask AI
Mask AI is an AI humanizer that converts AI-generated text into natural, human-sounding content designed to pass leading AI detectors like Turnitin and GPTZero. It also includes an AI detector, plagiarism checker and remover, and an AI writer, making it a complete toolkit for students, writers, and content teams.