AI-generated content is everywhere now. Blog posts, essays, even product descriptions — sometimes it’s hard to tell what’s written by a human and what came straight from a chatbot.

That’s why AI detectors are becoming more popular. But here’s the thing: there are so many of them, and not all work equally well. Some tools catch only obvious AI text. Others miss even basic machine-generated content.

So I decided to test a few of the most talked-about options: Smodin, Phrasly AI, Originality AI, GPTZero, and Sapling. The idea was simple — see which ai detector actually performs best when it comes to spotting AI content. Spoiler: one tool that really stood out in this test was AI detector by Smodin.

Smodin

Smodin is one of the most user-friendly tools I tested. The interface is clean, clear, and very intuitive. Everything works fast — paste your text or upload a file (they support .doc, .pdf, .xls, and more) and get results within seconds.

The free plan gives you 5 checks per week, each up to 5,000 characters. Paid plans start from $9/month if you need more. Plus, Smodin supports over 100 languages, which is a big advantage for non-English content. What really makes Smodin stand out is its accuracy. When I tested AI-generated text, it detected 92% of the content as AI.

Another strong feature is the way it shows results. Smodin highlights the exact parts of the text that look AI-generated and gives a clear percentage of AI vs human content. It also shows a confidence score, so you know how certain the tool is about its verdict. Simple, fast, accurate — Smodin handled the test really well.

Phrasly AI

Phrasly AI looks simple and works just as simply. The interface is clean, nothing distracting, and getting results doesn’t take long.

One of its nice features is the 2,000-word limit per check — enough for most typical tasks. After analyzing the text, Phrasly shows the overall percentage of AI content. Plus, it adds marks showing how this same text might perform in other popular detectors. It’s not a full report, but still an interesting extra.

Another good thing — Phrasly highlights specific sentences it thinks were generated by AI, so it’s easy to see which parts might raise questions. But the accuracy left me unimpressed. On fully AI-generated text, it showed only 51% AI. That’s really not enough if you’re counting on a tool to catch machine-written content. Phrasly is quick and easy to use, but definitely not the most reliable when it comes to results.

Originality AI

Originality AI feels like a more serious tool right from the start. The interface is clean and functional — nothing extra, everything focused on the check itself.

It shows the percentage of AI content and highlights AI-generated sentences, which is helpful. But the accuracy turned out to be average. In my test, it detected 64% of the fully AI-generated text as AI. Not bad, but not ideal either — especially when the whole text was clearly written by a machine.

Originality AI is simple to use, the check runs fast, but I expected better results considering how popular this tool is.

GPTZero

GPTZero has been around for a while, so I was curious to see how it would handle a basic AI text. The interface looks clean but a bit overloaded with extra details. For a quick check, it’s not the most convenient option. The free version lets you check short texts — up to 5,000 characters — and only shows the overall result without highlighting AI parts unless you register.

In my test, GPTZero detected 42% of the AI-generated text as human-written. That’s really low for a fully machine-generated article. It caught some AI signals but missed a lot. Overall, GPTZero works fine for human-written content, but with AI text, especially simple and raw, it struggles to give accurate results.

Sapling

Sapling looks nice and clean, very minimalistic. But the free version is quite limited — only 2,000 characters per check, which is less than most other tools offer. It shows the percentage of AI content and highlights the detected AI sentences, which is always a plus. But when it comes to accuracy, Sapling didn’t impress.

On fully AI-generated text, it detected only 74.7% as AI. That’s not terrible, but definitely not the best. The check also takes a bit longer compared to other tools, which isn’t great if you want quick results. Sapling feels simple and user-friendly, but accuracy leaves room for improvement, especially when dealing with clear AI content.

Which AI Detector Performed Best?

After testing all five tools, I can say one thing for sure — there’s no perfect AI detector. But some are clearly better than others. Most tools managed to catch at least some of the AI-generated content. But the difference in accuracy was huge. Phrasly and GPTZero, for example, struggled the most. They missed a big part of even simple, raw AI text — and that’s without any tricks or editing to make it sound more human.

Originality AI and Sapling handled the test better, but still left questions. They detected more AI content than others but didn’t always catch everything. And sometimes their checks felt slower or limited by character count.

Smodin, in this comparison, stood out clearly. It was fast, easy to use, and — most importantly — accurate. It didn’t just show the percentage of AI vs human content, but also highlighted exactly which parts of the text looked suspicious. That’s a huge help when you’re working with mixed or unclear content.

Of course, no tool will give you a perfect 100% guarantee. But if you want an ai detector that’s simple, clear, and does its job well, Smodin was by far the most reliable option in my test.