Undetectable AI vs. QuillBot: Can They Beat AI Detectors?

One of my biggest fears is getting falsely accused of using AI. For some, that may be irrational. However, after hearing what students go through after receiving a false positive, it’s become a legitimate worry to me what will happen to my future if I get accidentally flagged as using AI.

Fortunately, AI bypassers like Undetectable AI exist to fight against false positives. But I’ve always wondered: can older and more established paraphrasing tools like QuillBot avoid AI detection as well? 

That’s what we’re going to find out today. In this article, I’ll be comparing Undetectable AI and QuillBot’s features, price, output quality, and AI likelihood score.

What are Undetectable AI and QuillBot?

Undetectable AI is a paraphraser whose main goal is to humanize your input so that it can bypass AI detection. The way they do this is through removal of common AI patterns and addition of intentional “human” errors. For a full rundown of this product, I suggest reading our full review of it here.

On the other hand, QuillBot is a popular AI-powered writing tool that helps you improve your writing. It can paraphrase text, summarize articles, check grammar, create citations, and even translate. With different writing modes, it can adjust the tone and style of your writing depending on your needs. We also have a full review of QuillBot, which can be found here.

While they may look the same, these paraphrasers have completely different purposes. Undetectable AI exists to hide from AI detection, while QuillBot is a traditional paraphrasing tool that improves your writing.

Undetectable AI vs. QuillBot: Output Quality

If you read these outputs fully, you’ll get why I prefaced this section by saying that these paraphrasing tools exist for completely different reasons.

Undetectable AI’s output isn’t bad per se, but it is ridden with grammar and punctuation mistakes. For an AI bypasser, this is necessary to avoid detection. It’s like a stutter when we’re nervous or filler words when we run out of things to say — mistakes make us human, and Undetectable AI knows that.

The result is a good attempt at rewriting the original text, but not something you would use without proofreading. It also focused too much on changing words to synonym equivalents, rather than reworking the sentence structure or summarizing some elements. 

QuillBot’s output, as expected, is flawless. There’s a reason why people continue to use this tool, and it really shows in the text above. It understood perfectly the tone and intent of the original writing, which made it able to create a new version of it without relying too much on synonyms. It’s beautifully written, and most importantly, it makes sense.

Undetectable AI vs. QuillBot: AI Likelihood Scores

Test #1

Undetectable AI: Detected as human!
AI Likelihood Score: 0%

QuillBot: Detected as human!
AI Likelihood Score: 0%

Test #2

Undetectable AI: Detected as human!
AI Likelihood Score: 0.4%

QuillBot: Detected as machine-generated.
AI Likelihood Score: 100%

Test #3

Undetectable AI: Detected as human!
AI Likelihood Score: 0%

QuillBot: Detected as machine-generated.
AI Likelihood Score: 100%

Test #4

Undetectable AI: Detected as human!
AI Likelihood Score: 0%

QuillBot: Detected as machine-generated.
AI Likelihood Score: 98.5%

Test #5

Undetectable AI: Detected as human!
AI Likelihood Score: 0%

QuillBot: Detected as human!
AI Likelihood Score: 0%

Test #6

Undetectable AI: Detected as human!
AI Likelihood Score: 0%

QuillBot: Detected as machine-generated.
AI Likelihood Score: 100%

Test #7

Undetectable AI: Detected as human!
AI Likelihood Score: 0.6%

QuillBot: Detected as machine-generated.
AI Likelihood Score: 100%

Average AI Likelihood Score

Undetectable AI vs. QuillBot: Pricing

Undetectable AI's cost is dependent on two factors: word volume and payment method. For monthly subscriptions, costs range from $14.99 for 15,000 words to $209 for 380,000 words. Alternatively, annual plans start at $5 per month for 10,000 words and cap at $89.92 per month for 300,000 words.

QuillBot, on the other hand, costs $19.95 per month if you pay monthly, $13.33 per month if you pay every six months, and $8.33 per month if you pay annually. They also have a free version which lets you paraphrase text without pay if it’s under 125 words.

What’s The Verdict?

Normally, this is the part where I declare a winner, but I’m not going to do that today.

QuillBot and Undetectable AI exist in different categories and shouldn’t be compared (although, I guess I just did). It’s not fair to judge QuillBot on the basis of avoiding AI detection, and it’s not fair to judge Undetectable AI’s output quality.

However, here’s what I’ll say: they are both incredibly good at what they do. Undetectable AI’s average AI likelihood score of less than 1% across seven tests speaks volume of how good it is as a detection bypasser. QuillBot’s fluent and creative reimagining of the inputs are proof of how good it is as a traditional paraphraser.

So, as a buyer, all you need to do is decide what’s better for your needs. And if you’re unconvinced of how effective Undetectable really is, I suggest reading through some of our other comparison articles. Good luck!