AI writing tools have become mainstream, but they’ve also sparked a new problem, AI detectors. Many writers, students, and bloggers are turning to “AI humanizers” like Grubby AI to make their text sound more natural and bypass detection.
On paper, Grubby AI looks promising. It offers tools like Summarizer, Smart Notes, Quizzes, and Flashcards, making it more than just an AI text humanizer. But when we actually tested the free version, the results were not what we expected.
In this Grubby AI review, we’ll share our real testing experience, explain how it performs compared to competitors, and whether it’s worth paying for.
What Is Grubby AI Humanizer?
Grubby AI markets itself as an all-in-one writing and study assistant that can transform robotic AI-generated text into more natural human writing. The platform’s primary feature is the AI Humanizer, designed to rephrase, restructure, and smoothen AI content so it sounds like a real person wrote it.
In addition, Grubby AI includes some genuinely useful educational tools:
- Summarizer: Quickly shortens essays and articles into concise summaries highlighting the main ideas.
- Smart Notes: Converts long content into neat, bullet-pointed study notes with headings.
- Quizzes: Automatically generates multiple-choice and true/false questions from any given text — ideal for teachers.
- Flashcards: Builds question-and-answer cards for quick memory revision.
These add-ons make Grubby AI seem like a practical companion for students and educators, not just writers looking to avoid AI detection.
Testing the Free Version of Grubby AI
We tested Grubby AI’s free plan, which allows only 300 words per input. While the paid plan removes this limit, we found no reason to believe that upgrading would change the core output quality.
The dashboard itself deserves credit, it’s clean, minimalistic, and easy to navigate. Signing up is quick, and within seconds, you can paste your text and click “Humanize”. The interface clearly guides users, making it beginner-friendly.
However, the real test lies in how well it can “humanize” AI-generated content and that’s where things start to fall apart.
Grubby AI Humanizer Test Results
We took a few paragraphs generated by ChatGPT and ran them through Grubby AI’s free version. Initially, the tool seemed to work fine, but on reading the output, the problems were obvious.
Grubby AI often adds unnecessary filler words or replaces perfectly fine phrases with awkward alternatives. The text sometimes becomes harder to read or even changes meaning altogether. It reminds me of using QuillBot paraphrasing tool back in the days when there wasn’t any AI rather than an intelligent AI humanizer.
It performed somewhat better on shorter, simpler sentences. But for long or complex text, the results were inconsistent and clunky.
AI Detector Performance: Mixed and Misleading
We then evaluated the “humanized” text using two popular AI detectors:
- GPTZero: The original AI text scored 99% AI-generated, and after using Grubby AI, it only dropped to 57%. That’s still far from being considered human-written.
- Originality.ai: Surprisingly, it gave the rewritten text a 100% human-written score, showing how unreliable AI detectors can be.
This inconsistency reveals an important point, AI humanizers and detectors are not accurate science. One tool might flag text as 100% AI, while another claims it’s fully human.
In our case, Grubby AI didn’t convincingly “fool” AI detectors in a meaningful or consistent way.
Free vs Premium: Is the Upgrade Worth It?
Honestly, not really.
The free version is too limited, after one short test, you’re already prompted to pay. The premium version, starting under $10/month, removes the word limit and gives access to all tools, but the “humanized” output quality remains roughly the same.
If you only need quick summaries or flashcards, the premium plan might have some value. But if your goal is to make AI text sound more human, Grubby AI doesn’t justify the cost.
The Bigger Issue with AI Humanizers
It’s worth noting that AI humanizers as a category are deeply flawed. Most of them simply swap words or tweak phrasing rather than understanding tone, flow, and meaning.
Even worse, AI detectors often misfire, flagging genuine human writing as AI-generated simply because it uses simple vocabulary. Many users have reported that their personal essays or blog posts were wrongly flagged.
Ironically, tools like ChatGPT itself can rewrite content into a more natural and conversational form, and it’s completely free, with no restrictions on word count.
Pros and Cons
✅ Pros
- Easy-to-use interface and dashboard.
- Helpful educational tools (Summarizer, Notes, Quizzes, Flashcards).
- Affordable pricing (starting under $10/month).
- Improves basic readability for short content.
❌ Cons
- Adds unnecessary or awkward words.
- Struggles with long or technical sentences.
- Doesn’t consistently bypass AI detectors.
- Extremely limited free plan.
- Feels outdated, similar to old paraphrasing tools.
Not Worth the Hype
After extensive testing, our team at TechMetan found Grubby AI’s humanizer results underwhelming. While it offers a neat interface and valuable study tools, the core feature, making AI text sound human, simply doesn’t deliver.
Instead of natural, authentic writing, you often get awkwardly rewritten text that sounds more artificial than before.
If you’re a student, the extra tools like summarizer or quiz builder could be helpful. But for writers, bloggers, and professionals seeking a real “humanizer,” Grubby AI misses the mark.
Your best bet? Stick with ChatGPT for writing or other free rewriters that allow you to fine-tune tone, vocabulary, and structure manually and save your money.
⭐ Overall Rating: 2.5/5
Verdict: Grubby AI has potential as a study companion but fails as a true AI humanizer.
