AI Detectors.io vs GPTKit

AI Detectors.io analyzes text associated with major language models, returning an overall AI probability, confidence scores, and sentence-level results. The site also offers a humanizer, citation verification, plagiarism checking, grammar tools, and watermark removal. Its detector says it examines perplexity, burstiness, n-gram patterns, and stylometric fingerprints. The company reports 95.2% accuracy and 3.1% false positives from an April 2026 benchmark of 500 texts. The detector is trained and benchmarked on English; it returns scores for other languages, but those languages are outside that benchmark. Access is available through the web, Chrome extension, Microsoft Word add-in, and REST API. The Word add-in supports Word 2016 and later on Windows and Mac, as well as Word for the web, and can produce PDF reports. The free plan includes 10,000 words per month and a 500-word-per-use limit. Premium is listed at $8.33 a month, billed annually, with scans up to 25,000 words. Submitted text may be processed by third-party providers and retained as long as needed to support the service.

GPTKit analyzes submitted text and classifies it as human-written or ChatGPT-generated. It is available through a web interface and an API, with English currently supported. The maker says the detector combines six AI-based methods, was trained on 1 million datasets, and produces authenticity and reality reports. GPTKit reports approximately 93% accuracy based on testing 100K+ human and ChatGPT responses. The first 2048 characters of every request are free, including for guests; the Free Plan allows up to five requests per minute. Unlimited (Personal) costs $5 a month and supports two team members. Unlimited (Team) costs $10 a month, supports eight members, and includes API access. Unlimited (Institution) costs $20 a month, supports 20 members, and includes API access. Team credits can be shared. GPTKit says submitted text is temporarily stored and removed after detection; its policy says absolute security cannot be guaranteed.