As artificial intelligence models become more sophisticated, an AI test — which distinguishes between human-written and AI-generated text is becoming important. Whether for academic integrity, search engine optimization (SEO), or content authenticity, the need for a reliable AI test has grown. This article explores how you can check if text is written by AI and provides a detailed list of 10 tools designed for the task.
How an AI Test Works
Detecting AI-written content involves more than just a simple scan. While there is no single foolproof method, modern tools and manual checks look for specific patterns. AI detectors are trained on vast datasets of both human and AI-generated text. They analyze linguistic characteristics like perplexity (randomness or unpredictability of word choice) and burstiness (variation in sentence length and structure). Human writing tends to have higher perplexity and burstiness, while AI text can often be more uniform and predictable.
Manual checks for an AI test can also be revealing. Look for:
- Overly consistent tone and perfect grammar.
- Repetitive sentence structures or phrases.
- A lack of personal anecdotes, opinions, or emotions.
- Vague or generic statements that avoid deep specifics.
- Perfectly structured lists and flawless formatting.
For a more definitive AI test, dedicated software tools offer the best solution.
Top 10 Tools for an AI Test
Here are 10 of the most effective tools available to check if text is written by AI.
1. GPTZero
GPTZero is one of the most well-known detectors, built specifically to provide a reliable AI test for educators and writers. It provides a clear probability score, highlighting sentences that are most likely AI-generated. Its features include document uploads, batch scanning, and a writing feedback system to help users improve their work. Pricing includes a free plan with a character limit, while paid plans like “Essential” and “Premium” offer higher word counts, plagiarism scanning, and advanced analysis starting at around $10-$15 per month.
2. Originality.ai
Originality.ai is a comprehensive AI test tool designed for content publishers and SEO professionals. It not only detects AI but also includes a built-in plagiarism checker and readability score. Its key feature is its high accuracy and low rate of false positives, and it can scan entire websites. Originality.ai operates on a pay-as-you-go model, costing $0.01 per 100 words scanned, with a base subscription option also available for regular users.
3. Copyleaks
Copyleaks offers a robust, multi-faceted AI test that identifies text from a wide range of AI models, including paraphrased content. Its features are extensive, including AI and plagiarism detection in one scan, multilingual support in over 30 languages, and even an AI-generated image detector. Pricing for its AI detector starts with a Personal plan offering monthly credits, with Pro plans available for higher volume needs, making it scalable for both individuals and businesses.
4. Winston AI
Winston AI promotes itself as the “gold standard” for an academic AI test, boasting a 99.98% accuracy rate in detecting content from models like ChatGPT and Gemini. It features a sentence-by-sentence AI prediction map, the ability to scan uploaded documents and images using OCR, and generates shareable PDF reports. It uses a credit-based system, with a free trial of 2,000 credits and paid plans starting around $12 per month for 80,000 word credits.
5. Scribbr
Scribbr, powered by Turnitin, offers a highly accessible and free AI test for students. It requires no sign-up and allows unlimited checks for texts up to 1,200 words at a time. For more comprehensive needs, Scribbr bundles its premium AI detection with its well-regarded plagiarism checker. This premium service is priced per document, starting at $19.95 for small documents, and provides a more precise AI-generated percentage.
6. Turnitin
Turnitin is the industry leader for academic institutions and is the technology powering many other detectors. Its AI test is integrated directly into the grading workflow for educators, providing a report that highlights AI-generated text alongside its industry-leading plagiarism check. Because it is an enterprise-level tool sold directly to schools and universities, pricing is not publicly listed for individuals and is based on institutional contracts.
7. ZeroGPT
ZeroGPT is a popular and straightforward AI test tool that provides a percentage score indicating the likelihood of AI generation. It is widely used for its simplicity and offers a free tier with a generous character limit. Its features include text highlighting and batch file checking. For more advanced use, its Pro and Max plans offer higher character limits, PDF reports, and access to a suite of other writing tools like a summarizer and paraphraser, starting around $9.99 per month.
8. Writer.com
While primarily an AI writing assistant for businesses, Writer.com also offers a free AI test tool. It’s a simple copy-and-paste interface that is effective for quick checks, though it has a lower character limit than some other free tools. The main value of Writer.com is its full platform, which helps teams maintain a consistent brand voice, making the detector a small part of a larger enterprise solution with pricing available for “Starter” and “Enterprise” teams.
9. Sapling
Sapling is another AI assistant, primarily for customer-facing teams, that offers a free AI test detector. It can detect content from models like GPT-3.5 and GPT-4, effectively identifying text that sounds overly robotic or generic. The free version is limited to 2,000 characters. Upgrading to Sapling’s Pro or Enterprise plans removes these limits and integrates the detector with its other grammar and style correction tools.
10. Crossplag
Crossplag provides an integrated AI test and plagiarism checker, making it a useful tool for ensuring content originality on two fronts. It provides a simple, color-coded report that flags potential AI content and shows the AI probability. Crossplag offers a free plan with a 1,000-word limit. For more extensive use, it has a pay-as-you-go option as well as bundle and business plans for users who need to check a higher volume of documents.