Is Grammarly AI Detector Accurate

I’ve been testing Grammarly’s AI Detector to see if it lives up to its promise of spotting AI-generated content. While it’s a useful tool, its accuracy is often questioned. In my experience, it sometimes misses obvious AI content or flags human writing by mistake. So, is Grammarly AI detector accurate? In this review, I’ll share my findings, real-world test results, and why you might want to consider an alternative like Toolsmart’s Undetectable AI Rewriter.

Grammarly AI Detector Accurate or Overrated

What Is Grammarly AI Detector

Grammarly AI Detector is a tool designed to help identify whether a piece of content has been generated by an AI. I first came across it while looking for ways to verify the originality of my writing, especially given the rising concerns over AI-generated content. At first, I thought it would be a foolproof way to ensure my work was always flagged as authentic. However, after using it for a while, I realized that the tool's reliability isn’t as clear-cut as I had hoped. While it does a solid job with straightforward cases, I’ve noticed some gaps when it comes to more Advanced or cleverly edited AI content.

Grammarly AI Detector

Features

AI Detection Accuracy: Grammarly’s AI detector excels at spotting content that clearly follows AI-generated patterns. It uses sophisticated algorithms to analyze writing styles, sentence structure, and word usage, with a focus on detecting common traits found in AI writing.
Confidence Level: The tool assigns a confidence level to its detection, indicating how likely it is that the content is AI-generated. It uses a percentage scale ranging from low to high, making it easy to gauge the results.
Easy Integration: As part of the Grammarly suite, the AI detector integrates seamlessly into the writing and editing process, making it easy to check for AI content while you’re proofreading or composing your work.
Quick Analysis: Grammarly’s AI detector works quickly, allowing users to get results in seconds after submitting text.

Target Groups

Students: For those worried about AI tools influencing academic integrity, Grammarly is a great option to check for AI-generated assignments.
Writers & Content Creators: It’s essential for ensuring that your work is not flagged as AI-generated, especially when submitting content to platforms that scrutinize originality.
Educators: Grammarly’s AI detector can be helpful for teachers who need to verify the authenticity of student submissions.
Publishers & Editors: Editors can use the tool to maintain standards of originality and ensure that submitted pieces haven’t been AI-generated.

Limitations

Inaccurate with Subtle AI Content: While it’s great at spotting obvious AI writing, it struggles with more nuanced content, especially when AI-generated text is cleverly edited or blended with human-written sections.
False Positives: Sometimes, Grammarly mistakenly flags human-written text as AI-generated, particularly when the writing is formal, repetitive, or follows certain patterns that mimic AI’s style.
Limited Free Use: While Grammarly’s AI detector is available in both free and premium versions, the premium version unlocks more features and deeper analysis. Free users have access to limited functionality.
Lack of Contextual Understanding: The tool focuses primarily on surface-level characteristics like sentence structure and phrasing. It doesn’t always take into account the deeper meaning or context of the text, which can lead to misidentifications.

Testing Grammarly AI Detector—Real-World Examples

When it comes to AI detection, I knew I had to put Grammarly’s AI detector to the test with a variety of content to see just how well it performed. After all, I’ve seen plenty of tools that claim they can spot AI-generated text, but the real question is: how well can they detect different levels of AI involvement, and is Grammarly AI detector accurate? So, I decided to run a few tests with three types of content: purely AI-generated text, human-written text, and a mix of both. Here’s what I found out about how accurate is Grammarly AI detection.

Grammarly AI Report

Test 1: Pure AI-Generated Text

I wanted to start simple, so I took a 100% AI-generated piece of content from ChatGPT, with no human edits or influence. I wanted to see how Grammarly would handle a piece of text that was clearly and purely created by an AI model. If it were to flag it as having a high percentage of AI content, then that would partially answer my question Is Grammarly AI detector accurate?

Result: Grammarly flagged the content with high confidence as AI-generated.
Confidence Level: High
Grammarly’s Comment: "This content appears to be generated by AI, with a low likelihood of human authorship."
Analysis: I was impressed here. Grammarly was able to spot the AI-written content easily, and the confidence level was solid. This isn’t surprising, given that AI text, especially from models like ChatGPT, often follows patterns that are easy to detect with a bit of analysis. In this case, it worked as expected. However, it’s important to note that this was pure, unedited AI content, so it was easy for Grammarly to pick up on it.

100% AI Result

Test 2: Human-Written Text

Next, I ran a piece of my own writing through Grammarly’s AI detector. This test was crucial because I wanted to see if Grammarly could accurately differentiate between human writing and AI content. Could it avoid false positives and truly recognize my personal writing style?

Result: Grammarly flagged the content as human-written with no AI involvement.
Confidence Level: High
Grammarly’s Comment: "This content has been written by a human, with no indication of AI generation."
Analysis: No surprises here either. Grammarly did a great job of recognizing that my human-written text wasn’t AI-generated. The confidence level was solid, and there were no signs of confusion. Grammarly’s analysis was spot on, with its results aligning perfectly with what I expected from purely human writing.

Human Written text Result

Test 3: Mixed AI + Human-Written Content

For my final test, I took a hybrid approach. I asked ChatGPT to generate a short essay on Jazz music, then I reviewed and edited the text, paraphrasing, adding my tone, and refining the structure. The idea was to see how well Grammarly could handle mixed-content situations where there’s both AI input and human involvement. If it could pass this test, that would answer that is Grammarly AI checker accurate or not.

Result: Grammarly flagged the content with medium confidence as AI-generated, but it wasn’t fully certain.
Confidence Level: Low
Grammarly’s Comment: "This content shows signs of being AI-generated but also contains elements of human input. Further analysis may be needed."
Analysis: Here’s where things got a bit trickier. Grammarly wasn’t as confident in its detection, and I can understand why. When you mix AI-generated content with human edits, it becomes harder for any AI detection tool to accurately assess it. The confidence level was lower, and while it flagged the text as potentially AI, it also acknowledged that human input was present. This test highlighted one of Grammarly’s limitations—it’s great with purely AI-generated or human-written text, but when it comes to a mix, it doesn’t always provide a clear answer.

Paraphrased text result

Test Type	Grammarly AI Detector Results	Accuracy
Pure AI	Correctly flagged as AI with a low human score	High accuracy, strong confidence
Human-Written	Identified as human-written with a high human score, no false positives	Reliable, with minimal risk of error
Mix of AI + Human	Varying results, sometimes flagged as AI or human	Moderate accuracy, lower confidence

Toolsmart’s Undetectable AI Rewriter Helps You Bypass Detection

After running a few tests with Grammarly’s AI detector, I realized that while it does a good job in some cases, it’s not perfect, especially when it comes to mixed content and especially when i digged in deeper and wanted to find out does Turnitin detect Grammarly I found out that it easily detected text paraphrased by Grammarly which got me in trouble with one of my professors during my undergrad. As compared to Turnitin, it wasn't as accurate. That’s when I came across Toolsmart’s Undetectable AI Rewriter, and I must say, it’s been a game-changer. The tool promises to help rewrite AI-generated content in a way that makes it more natural and less detectable. After giving it a try, I was impressed by how easy it was to use and how it kept my voice intact, even when working with AI-generated content. What’s even more important is that it is free and doesn’t require a download or bombard you with tons of ads, which is perfect for students.

Toolsmart AI Tools

Pros:

Easy to use with a user-friendly interface
Refines content without changing your voice
Works offline, so you can edit your drafts at any time
Absolutely free to use with zero ads
No stress of being tracked

Steps:

Now, let's look at how to use this tool. In simple tools that you can use even if you're a beginner to the internet.

Use Word, Excel, and PPT for FREE

Step 1: Go to Toolsmart’s Undetectable AI page to humanize your text.

Toolsmart Undetectable AI

Step 2: Copy the text checked by Grammarly and paste it into the Toolsmart input box.

Paste text

Step 3: Choose your tone. Select from Friendly, Formal, or Persuasive and others depending on your choice and occasion. You also change the humanization level.

Select mode

Step 4: Click “Humanize”. Watch as your text transforms into a more natural version.

Click Humanize

Step 5: Your humanized/updated text will appear on the right side, which you can copy and use.

Humanized text

No matter the task, whether I’m writing a formal report, a casual post, or something more scholarly, Toolsmart Undetectable AI has been a perfect fit for me. It adjusts my content in just the right way, leaving it human-like and exactly how I want it to be.

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Microsoft-like interface. Easy to learn. 100% Compatibility.
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Khadija Khan

FAQs

Q1: Is Grammarly AI Detector 100% accurate?

Not really. Grammarly's AI Detector does a solid job at catching obvious AI-generated text, but it can sometimes miss content that's been cleverly rewritten or edited.

Q2: Why does the Grammarly AI Detector sometimes flag my original writing as AI-generated?

It happens because of certain writing styles or repetitive phrasing, or if the tone is a bit too formal, it can make your text resemble AI patterns, which leads to false positives.

Q3: Can I use Toolsmart’s Undetectable AI Rewriter for rewriting social media posts?

Definitely! Toolsmart’s Undetectable AI Rewriter works for all kinds of content, including short posts for social media.

Q4: Is Grammarly AI Detector free to use?

Yes, you can use Grammarly’s AI detector for free, though some features might only be available with the premium version, depending on your plan.

Q5: Is Toolsmart’s Undetectable AI free to use?

Yes! Toolsmart’s Undetectable AI is completely free and doesn’t require any sign-ups or registrations.

Q6: How long does it take for Toolsmart’s Undetectable AI to polish my text?

It’s super fast! Toolsmart can process and refine up to 1500 words in just a few seconds.

Why I Trust Toolsmart's Undetectable AI Rewriter Over Grammarly's AI Detector

In this article, I tested Grammarly’s AI Detector and found it works well for obvious AI text but struggles with mixed content. For more reliable results, I recommend Toolsmart’s Undetectable AI Rewriter. It quickly humanizes AI-generated content while keeping my voice intact, making it undetectable. It's been a game-changer for me in ensuring my work stays original and safe from detection.

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