Undetectable AI is one of the largest AI humanizers on the market. It markets itself as an AI humanizer that bypasses AI detectors, pairs it with its own AI detector, and claims more than 24 million users.
With that much reach, the key question is simple: does it actually work?
This review covers:
- The AI humanizer and how it performs against major detectors
- The AI detector
- Pricing, plans, and the free trial
- User reviews
- How it compares to Verva's AI humanizer
Key Findings
- The AI humanizer failed every detector we tested, including Turnitin, GPTZero, ZeroGPT, Copyleaks, and QuillBot.
- The AI detector gave inaccurate results, labeling human writing as 57% AI and ChatGPT text as 99% human.
- Plans start at $9.99 per month, or $5.00 per month billed yearly. The free trial is limited to 250 words.
- Undetectable AI holds a 3.5-star rating on Trustpilot from about 980 reviews, with recurring complaints about subscriptions.
What Is Undetectable AI?
Undetectable AI is marketed as both an AI humanizer and an AI detector. You paste in AI-generated text, choose your settings, and the humanizer rewrites it to be "undetectable." The platform then shows an AI likelihood score for the result.
It's aimed at students, content creators, and professionals who want AI-assisted writing to pass AI detection. The interface is simple: paste your text, click Humanize, and check the result.
Over time, Undetectable AI has also added dozens of other tools, including essay writers, paraphrasers, citation generators, a job applier, resume and cover letter generators, a grammar checker, a translator, and image, voice, and video detectors. The variety is broad, but the humanizer and detector remain its core products, so that's where we focused our testing.
AI Humanizer
We used the Undetectable mode to humanize an essay generated by ChatGPT, then checked the output with five major AI detectors.
| AI Detector | Result |
|---|---|
| GPTZero | ❌ 100% AI |
| ZeroGPT | ❌ 100% AI |
| Copyleaks | ❌ 100% AI |
| QuillBot | ❌ 100% AI |
| Turnitin | ❌ 100% AI |
Undetectable AI's humanizer failed to bypass every major AI detector. This is notable because ZeroGPT's results page includes a "Humanize Text" button that promotes Undetectable AI, yet text humanized with Undetectable AI was still flagged as 100% AI by ZeroGPT.
Undetectable AI vs Verva
We also ran a GPT-5 sample through both Undetectable AI and Verva's free AI humanizer, then checked each result against the same detectors.
| Detector | Original GPT-5 Text | Undetectable AI | Verva |
|---|---|---|---|
| Turnitin | 100% AI | 100% AI | 0% AI |
| GPTZero | 100% AI | 100% AI | 1% AI |
| ZeroGPT | 98% AI | 90% AI | 0% AI |
| Copyleaks | 100% AI | 100% AI | 0% AI |
Undetectable AI only lowered ZeroGPT's score slightly and left the text flagged everywhere else. Verva's output passed every detector.
Text Quality
The rewrites were low quality, with inconsistent phrasing and poor structure. They introduced sentence fragments and new grammatical errors. Rather than sounding more human, the text became noticeably less natural.
AI Detector
Undetectable AI's detector is powered by TruthScan, which is operated by the same founder.
In our tests, the results were inaccurate:
| Text Tested | Result |
|---|---|
| Human-written text | 57% AI |
| ChatGPT-generated text | 99% human |
| Text humanized by Undetectable AI | 60% AI |
The detector misjudged both human and AI writing, and it also flagged text produced by Undetectable AI's own humanizer. For reliable detection, established tools like GPTZero or Turnitin performed far better.
Pricing
Undetectable AI offers monthly and yearly plans, based on how many words you need each month.
| Words per Month | Monthly | Billed Yearly |
|---|---|---|
| 10,000 | $9.99 / month | $5.00 / month ($60 per year) |
| 20,000 | $19.00 / month | $9.50 / month ($114 per year) |
| 35,000 | $31.00 / month | $15.75 / month ($189 per year) |
| 50,000 | $42.50 / month | $21.25 / month |
Larger plans scale up to 380,000 words per month, and custom business plans are available.
All plans include:
- AI humanizer
- Unlimited AI detection
- Writing level matching
- Unlimited Human Auto Typer
- API access
Free trial: There is no free plan. To try the humanizer, you start a free trial, which requires signing up and is limited to 250 words. Additional use requires activating a paid plan.
Free Trial and Cancellation
Because the free trial starts the sign-up for a paid plan, it's worth reading the terms carefully and noting when the trial ends.
When we tried to delete our account, a chat popup offered 1,000 extra words to stay, along with a message pleading with us not to cancel. Retention offers like this are common, but it's worth knowing to expect one if you plan to cancel.
User reviews frequently mention similar issues:
- Being charged soon after starting a free trial
- A confusing cancellation process
- A trial converting into a yearly subscription
If you try Undetectable AI, check which plan the trial renews into and cancel before it ends if you don't plan to continue.
User Reviews
Undetectable AI has a 3.5-star rating on Trustpilot from about 980 reviews.
Positive reviews often praise the customer support team as polite and quick to respond. Negative reviews most often focus on:
- Unexpected subscription charges, especially after a free trial
- Humanized text that still gets flagged by AI detectors
- Rewrites that read awkwardly
Pros and Cons
Pros
- Simple, easy-to-use interface
- Built-in AI detector with unlimited scans
- Wide range of extra writing tools
- Responsive customer support
Cons
- AI humanizer failed every major detector we tested
- Rewrites are unnatural and introduce errors
- AI detector gave inaccurate results
- No free plan, and the free trial is limited to 250 words
- Frequent complaints about trial billing
Final Verdict
Undetectable AI has strong branding, a large user base, and a polished interface. However, its core products, the AI humanizer and AI detector, did not hold up in our testing. The humanizer failed every major AI detector, and the detector misjudged both human and AI text.
Rating: 2.2/5
We do not recommend Undetectable AI as an AI humanizer or AI detector. If you need AI text that passes Turnitin, GPTZero, and other detectors, try Verva's AI humanizer.
Frequently Asked Questions
Does Undetectable AI bypass Turnitin?
No. In our testing, text humanized with Undetectable AI was flagged as 100% AI by Turnitin.
Does Undetectable AI bypass GPTZero?
No. GPTZero flagged Undetectable AI's output as 100% AI.
How much does Undetectable AI cost?
Plans start at $9.99 per month for 10,000 words, or $5.00 per month when billed yearly ($60 per year).
Does Undetectable AI have a free plan?
No. It offers a free trial limited to 250 words, which requires signing up. Additional use requires a paid plan.
Is Undetectable AI's AI detector accurate?
Not in our tests. It labeled human writing as 57% AI and ChatGPT text as 99% human.
What is a better alternative to Undetectable AI?
Verva's AI humanizer passed Turnitin, GPTZero, ZeroGPT, and Copyleaks in the same test where Undetectable AI failed. You can also check your text with the free Verva AI detector.
