Undetectable AI vs. Rewritify: What’s the Best AI Humanizer in 2025?

Between AI detection paranoia and the struggle to make ChatGPT sound less... well, ChatGPT-ish, tools like Undetectable AI and Rewritify have carved out quite the niche for themselves. They promise to take robotic text and infuse it with those little human quirks we all have in our writing — but do they actually deliver?

As someone who's been down this rabbit hole, I had the exact same question. That's why I've put both platforms head-to-head across readability, detection tests, and pricing. The results? Let's just say that while both tools do what they claim, one of them consistently outperforms in ways that made me do a double-take.

But which one? Let’s find out.

What are Undetectable AI and Rewritify?

Most students have gone through false accusations of using AI for their schoolwork. AI humanizers are made to resolve that.

Undetectable AI and Rewritify are AI humanizers and bypassers which turn something that reads like AI into something more human-sounding. This is possible by removing common AI markers (repetitions, overused AI words, and hallucinations) and adding a few intentional errors to humanize your content.

You can read more about Undetectable AI in our full review here.

Undetectable AI vs. Rewritify: Readability

The first thing that jumps out is tone and clarity. Undetectable AI leans simple and direct, almost stripped to the bone, while Rewritify is more puffed up — sometimes awkwardly so. I mean — "elm trees, once ubiquitous, are characterized by their vase-like shape" sounds like it came from a thesaurus-fueled fever dream. 

Rewritify takes liberties with phrasing ("exterminated numbers"? Really?) that muddy meaning instead of clarifying it. Grammar-wise, it’s mostly intact, but the sentence construction feels forced and unnatural.

Undetectable AI, on the other hand, isn’t flawless — it drops articles ("American elm" instead of the American elm) and has the clunky line "Elms shade and live in," which reads like someone hit "shuffle" on a grammar app. Still, it's more faithful to the original and feels easier to digest. The core message stays intact, even if the polish is missing. 

Between the two, Undetectable AI is rough around the edges, but Rewritify overreaches and ends up sounding robotic. If we’re going for closeness to the source and readability, Undetectable AI takes the win — hands down.

Undetectable AI vs. Rewritify: Bypassing AI Detection

Test #1

Undetectable AI: Successfully passes as human!
AI Likelihood Score: 0%

Rewritify: Successfully passes as human!
AI Likelihood Score: 0%

Test #2

Undetectable AI: Successfully passes as human!
AI Likelihood Score: 0.1%

Rewritify: Detected as AI-generated
AI Likelihood Score: 100%

Test #3

Undetectable AI: Successfully passes as human!
AI Likelihood Score: 0.0%

Rewritify: Successfully passes as human!
AI Likelihood Score: 0%

Test #4

Undetectable AI: Successfully passes as human!
AI Likelihood Score: 0%

Rewritify: Successfully passes as human!
AI Likelihood Score: 1%

Test #5

Undetectable AI: Successfully passes as human!
AI Likelihood Score: 0%

Rewritify: Detected as AI-generated
AI Likelihood Score: 100%

Test #6

Undetectable AI: Successfully passes as human!
AI Likelihood Score: 0.9%

Rewritify: Successfully passes as human!
AI Likelihood Score: 0%

Test #7

Undetectable AI: Successfully passes as human!
AI Likelihood Score: 0%

Rewritify: Detected as AI-generated
AI Likelihood Score: 100%

Overall Score

Undetectable AI vs. Rewritify: Pricing

Let's talk about pricing because — let's be real — your wallet matters. 

Undetectable AI’s pricing structure is pretty straightforward: $5/mo for their yearly plan with a 50% discount or $19/mo for their monthly option. Both plans come with a word limit — 10,000 and 20,000 words respectively — with the ability to scale up to 380,000 words if needed.

On the flip side, Rewritify offers three tiers: Basic at $14/mo for 5,000 words, Ultimate at $24/mo for 50,000 words, and an Unlimited option at a whopping $49/mo. The value proposition is crystal clear here — Rewritify’s Ultimate plan gives you 5x the words compared to their Basic plan for less than double the price. 

But here's where it gets interesting: Undetectable AI’s yearly plan at $5/mo for 10,000 words absolutely demolishes Rewritify’s Basic plan which charges nearly triple for half the words.

So, Which Should You Pick?

I broke this down into three categories: readability, bypassing AI detection, and pricing — unsurprisingly, Undetectable AI won all three.

It’s just miles better than the closest competition. The only thing Undetectable AI lacks is perfect readability, and it’ll be hard not to recommend it to everyone.

As for Rewritify, it’s really good, but I just don’t think it’s a worthwhile expense. It doesn’t do anything that Undetectable AI can’t, and it’s less flexible in pricing. Not to mention that they’re a bit stingy when it comes to free trials (80 words maximum per account compared to Undetectable AI’s 200 words + daily spins for free words), which makes their tool more inaccessible.

One thing before you go: always use these tools for good. With that in mind, I highly recommend checking this article out. Good luck!