GPTinf

Suikou AI is a global AI writing naturalizer (humanizer) with a built-in AI text detector. Paste AI-generated text and it rewrites it into natural, human-sounding prose in three registers — casual, academic, and business — in seconds. The detector scores any text for AI probability, perplexity, and burstiness so you know how "machine" your writing reads. Built by a Kyoto NLP researcher, Suikou AI's Japanese support is best-in-class: a morphology-aware engine that generic humanizers can't match, while working great across English and other languages too. Free tier covers 500 words/day; paid plans start at $9.99/mo, with a 50% student discount via .edu email verification.

UndetectedGPT is a content-creation platform designed to help users generate or convert text so that it is indistinguishable from human-written material and avoids detection by AI-detector tools. The platform offers three core tools, AI Humanizer, which takes existing AI-generated text and reworks it to emulate human writing style with natural flow, tone variation and less mechanical structure; AI Stealth Writer, which generates new text from prompts while optimizing it to pass undetected by popular AI-detection systems; and AI Detector, which evaluates your text against multiple detectors and provides a score and analysis of how likely the text is to be flagged. Users can paste AI-generated content to be "humanized," choose a tone (casual, balanced, technical, formal), and then output a final version claimed to present “100% human-written” results for publishing, academia, or marketing, while remaining optimized for SEO and readability.