$16M/year Norton AntiVirus for AI text

TL;DR: With the launch of ChatGPT triggering a panic over AI-generated essays in education, GPTZero launched as an AI detection platform that analyzes text for statistical patterns matching LLM outputs. Sacra estimates GPTZero reached $16M in ARR by April 2025, up from $6.8M at the end of 2024. For more, check out our full report and dataset on GPTZero.

Key points via Sacra AI:
- The November 2022 launch of ChatGPT enabled students to generate whole essays with a prompt, sparking a panic in education and inspiring the launch of GPTZero (founded in 2023), an AI detection web app that uses a fine-tuned language model to measure how closely each sentence in a text matches the statistical, next-token patterns learned from millions of LLM outputs. Finding initial product-market fit with teachers, GPTZero monetizes through tiered subscriptions starting at $15/month for 150,000 words (Essential) up to $24/month for 300,000 words plus plagiarism detection (Premium), with enterprise deals like their American Federation of Teachers partnership providing access to 1.7 million educators.
- Expanding from academia to media for verifying written articles as human writing, Sacra estimates that GPTZero reached $16M in ARR by April 2025, up 135% from $6.8M at year-end 2024. Compare to education-focused plagiarism detector Turnitin at a Sacra-estimated $203M in revenue for 2024, up 10% year-over-year, which has bundled AI detection into its existing enterprise contracts—in contrast, GPTZero's PLG-esque freemium model (10,000 words free, then $15-45/month) captures individual teachers and grows bottom-up into larger deals.
- Like Norton Antivirus riding the 1990’s rise of PC malware, GPTZero is riding the explosion of adversarial ChatGPT copy & paste—and not unlike how Windows bundled antivirus in the OS, GPTZero’s next phase of competition will come from the threat of bundling via 1) incumbents like Turnitin in GPTZero’s core vertical of education, and 2) watermarking in the underlying LLMs by OpenAI and Gemini or new models without signatures at all. GPTZero’s counter move is to rebundle AI text detection with Grammarly (spell check, grammar & style, $375M ARR up 19% YoY), hallucination detection, fact checking, and more to serve concrete verticals & workflows across HR (screening AI-written resumes & cover letters), government (authenticating public comments), and ML engineering (filtering synthetic training data) in addition to education & media.
For more, check out this other research from our platform:
- GPTZero (dataset)
- Copy.ai (dataset)
- Jasper (dataset)
- Harvey (dataset)
- Jenni AI: the $5M/year Chegg of generative AI
- AI writing goes enterprise
- Harvey at $50M ARR
- David Park, CEO and co-founder of Jenni AI, on prosumer generative AI apps post-ChatGPT
- Chris Lu, co-founder of Copy.ai, on generative AI in the enterprise
- Grant Lee, co-founder of Gamma, on rethinking the primitives of presentations
- Jon Noronha, co-founder of Gamma, on building AI-powered slides