Undetectable AI vs. Decopy AI: AI Image Detection Face-Off

There’s a quiet arms race happening right now in the world of AI tools — and it’s not just about writing anymore.

AI image generation has gotten so good that it’s no longer obvious what’s real and what’s not. Don’t even get me started on Sora and their AI video feed. As a result, tools built to detect AI visuals are becoming just as critical as the ones built to generate them.

Undetectable AI and Decopy AI are two platforms that both started in the text detection space — but are now expanding into visual territory. Both claim their detectors can spot whether an image was made by AI. The question is: how well do they actually do it?

That’s what I wanted to find out.

So I ran both tools through a set of AI-generated images to see how they stack up. But before we get into that (which I’ll handle in the testing section below), let’s talk about what these two tools actually offer and how they approach AI detection.

What is Undetectable AI?

Undetectable AI has come a long way from being just a humanizer for text. In 2025, it’s become a complete content intelligence platform with a new set of tools — from its Writing Style Replicator to newer features like a Resume Builder and an Image Detector.

The AI Image Detector, powered by TruthScan, works much like the rest of Undetectable AI’s lineup — fast, clean, and privacy-safe. It scans an image, evaluates its pixel-level data, and returns a probability score indicating whether the image was generated or edited by AI.

It’s simple to use. Upload an image, click detect, and within seconds, you’ll get a clear verdict — often accompanied by a short explanation of what tipped the system off (lighting inconsistencies, texture uniformity, pattern repetition, etc.).

Undetectable AI’s advantage has always been its focus on humanization. Unlike most tools that try to catch AI, this one understands what makes content look human — and reverses that understanding to detect when something feels off. It’s fast, web-based, and intuitive — the kind of detector you’d expect from a company that knows both sides of the AI equation.

What is Decopy AI?

Decopy AI, on the other hand, started out as a simple writing tool before branching out into a wide range of AI-related utilities. Its current lineup includes an AI Detector, AI Humanizer, and AI Summarizer — and of course, its AI Image Detector.

The Decopy AI Image Detector works because it’s trained on over 10 million images. It analyzes pixel noise patterns, texture uniformity, and metadata. The platform is not just free — it’s precise and built around authenticity verification, which makes sense given how it markets itself to educators, researchers, and SEO professionals. 

Undetectable AI vs. Decopy AI: Detection Comparison

Test #1

Undetectable AI: Correctly identified Midjourney image as machine-generated.
AI Image Likelihood: 97%

Decopy AI: Incorrectly identified Midjourney image as human-created.
AI Image Likelihood: 5%

Test #2

Undetectable AI: Detector unsure.
AI Image Likelihood: 48%

Decopy AI: Incorrectly identified Midjourney image as human-created.AI Image Likelihood: 0%

Test #3

Undetectable AI: Correctly identified Midjourney image as machine-generated.
AI Image Likelihood: 97%

Decopy AI: Correctly identified Midjourney image as machine-generated.
AI Image Likelihood: 100%

Test #4

Undetectable AI: Correctly identified Midjourney image as machine-generated.
AI Image Likelihood: 97%

Decopy AI: Incorrectly identified Midjourney image as human-created.
AI Image Likelihood: 0%

Test #5

Undetectable AI: Correctly identified Midjourney image as machine-generated.
AI Image Likelihood: 97%

Decopy AI: Incorrectly identified Midjourney image as human-created.
AI Image Likelihood: 4%

Test #6

Undetectable AI: Correctly identified Midjourney image as machine-generated.
AI Image Likelihood: 98%

Decopy AI: Incorrectly identified Midjourney image as human-created.
AI Image Likelihood: 36%

Test #7

Undetectable AI: Correctly identified Midjourney image as machine-generated.
AI Image Likelihood: 94%

Decopy AI: Incorrectly identified Midjourney image as human-created.
AI Image Likelihood: 0%

Test #8

Undetectable AI: Correctly identified Midjourney image as machine-generated.
AI Image Likelihood: 98%

Decopy AI: Incorrectly identified Midjourney image as human-created.
AI Image Likelihood: 0%

Overall Score

The Bottom Line

After running both tools through multiple image tests, the difference in accuracy wasn’t even close. Undetectable AI scored an impressive 90.75% correctness. Decopy AI, meanwhile, landed at 18.125%, struggling to correctly classify even some of the more obvious AI visuals. 

Undetectable AI, on the other hand, feels ready. It’s fast, accurate, and surprisingly nuanced in how it spots subtle patterns that give AI images away — like over-smooth textures, perfect symmetry, or uncanny lighting. It doesn’t just detect AI, it understands what makes an image feel human.

If accuracy is your main priority, this isn’t a close race. Undetectable AI doesn’t just win — it dominates.

Decopy AI has potential, but right now, it’s not even playing in the same league.