Students want to avoid academic penalties<\/a>. Content creators need to bypass detection tools. <\/p>\n\n\n\n Businesses want authentic-sounding copy.But not all humanizers<\/a> are created equal. <\/p>\n\n\n\n Today, we’re diving deep into Grammarly’s AI humanizer feature to see if it lives up to the hype or if you’d be better off looking elsewhere.<\/p>\n\n\n\n Key Takeaways<\/strong><\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Grammarly’s AI humanizer is the newer sibling in its product family. <\/p>\n\n\n\n While the company made its name with its grammar-checking tool, it has since expanded into AI detection and text humanization.<\/p>\n\n\n\n The feature works as part of Grammarly’s broader writing assistant. <\/p>\n\n\n\n You paste in your AI-generated text, and it attempts to rewrite it in a more natural, human-sounding way. <\/p>\n\n\n\n The goal? Making your content undetectable to AI detection tools.<\/p>\n\n\n\n Sounds simple enough, right?<\/p>\n\n\n\n The thing is that Grammarly didn’t build this as its core product. <\/p>\n\n\n\n It’s more like a side feature tucked into their grammar tool, and that distinction matters more than you might think.<\/p>\n\n\n\n The process is straightforward. You input your AI-generated text into Grammarly’s interface. <\/p>\n\n\n\n The tool analyzes the content and suggests rewrites to make it sound more human.<\/p>\n\n\n\n The algorithm looks for patterns that scream, “AI wrote this.” These include repetitive sentence structures, overly formal language, and predictable word choices. <\/p>\n\n\n\n Then, it attempts to fix these issues.<\/p>\n\n\n\n Grammarly’s approach focuses heavily on grammar and style<\/a> corrections rather than deep structural changes. <\/p>\n\n\n\n This makes sense given their foundation, but it’s not always what you need for effective humanization.<\/p>\n\n\n\n Grammarly markets its humanizer for several scenarios:<\/p>\n\n\n\n The tool also targets users who want to maintain their voice while using AI assistance. <\/p>\n\n\n\n The idea is to allow for the efficiency of AI while preserving human authenticity.<\/p>\n\n\n\n But what they want and what they can deliver are two different things.<\/p>\n\n\n\n Here’s where we get into the nitty-gritty. We followed ZDNet’s benchmark methodology<\/a> to test whether Grammarly can actually fool AI detectors. <\/p>\n\n\n\n ZDNet previously highlighted Undetectable AI as one of the few tools achieving perfect scores, so we used that as our comparison standard.<\/p>\n\n\n\n We prepared two text samples for testing:<\/p>\n\n\n\n Both samples went through Grammarly’s AI detector and Undetectable AI’s detector for comparison.<\/p>\n\n\n\n Grammarly Detector \u2013 Human Written Result:<\/strong><\/strong><\/p>\n\n\n Undetectable AI Detector \u2013 Human Written Result:<\/strong><\/p>\n\n\n Both tools correctly identified our samples. Grammarly’s binary approach gave us a definitive “100% AI” label. Undetectable AI provided nuanced probability scoring with “92% AI likelihood.”<\/p>\n\n\n\n Grammarly Detector \u2013 GPT Output Result:<\/strong><\/p>\n\n\n Undetectable AI Detector \u2013 GPT Output Result:<\/strong><\/p>\n\n\n Here’s what we learned: Grammarly can detect AI content accurately. <\/p>\n\n\n\n But detection is only half the battle. The real test comes with humanization.<\/p>\n\n\n\n Undetectable AI’s probability system offers more actionable insights. <\/p>\n\n\n\n Instead of just saying “this is AI,” it shows how strongly the text leans toward artificiality. <\/p>\n\n\n\n
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\n\n\n\nWhat Is the Grammarly AI Humanizer?<\/h2>\n\n\n
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Intended Use Cases<\/strong><\/h3>\n\n\n\n
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Does It Really Fool AI Detectors?<\/h2>\n\n\n\n
The Test<\/strong><\/h3>\n\n\n\n
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The Results<\/strong><\/h3>\n\n\n\n
Content Type<\/strong><\/td> Grammarly Result<\/strong><\/td> Undetectable AI Result<\/strong><\/td> Correct?<\/strong><\/td><\/tr> Human-Written<\/td> 0% AI (Human)<\/td> 94% Likely Human<\/td> \u2705 Both Correct<\/td><\/tr> GPT-Generated<\/td> 100% AI<\/td> 92% AI Probability<\/td> \u2705 Both Correct<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n ![\"\"](\"https:\/\/undetectable.ai/blog\/wp-content\/uploads\/2025\/09\/Grammarly-AI-Humanizer-002-1024x377.jpg\")
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