The 4 Best AI Detector Tools Writers Should Use

Not all AI detector tools work the same. Each one is trained to identify different writing patterns from different AI models. That’s why one tool may show “high AI content” while another one shows “low AI content” for the same text you provide.
So, the smart thing to do is choose your detector based on the AI tool you used to generate or the type of writing you want to check.

1. Copyleaks 

Copyleaks is one of the most advanced detectors online. It is especially good at spotting content from:

• OpenAI models (GPT-2, GPT-3, GPT-4)

• Claude (Anthropic)

• Google Gemini

It tries to identify the exact model used. But since Copyleaks uses some third-party APIs, false positives can happen, especially with short content.

2. Grammarly AI Detector 

Many people are unaware of this, but Grammarly has an AI detector built into its editor. What it’s good at:

• Detecting mixed human + AI writing

• Short social media captions

• Lightly edited AI text

It may not always identify the exact AI model, but for general writing, if Grammarly shows below 20% AI, we consider it safe.

3. GPTZero

GPTZero became famous among teachers and universities. Best for detecting:

• School essays and Assignments
• ChatGPT, GPT-5, GPT-4, GPT-3, Gemini, Claude, Llama, Deepseek, and AI services based on those models
• Research-style writing

It looks at “burstiness” and “perplexity,” which means it checks whether the writing flows like a human or stays too consistent like a machine.

4. Originality.ai 

If you write long blog posts, SEO articles, or website content, this tool is very reliable. Best at detecting:

• Most Accurate AI Detector for GPT-5, ChatGPT, Claude 4, Gemini 2.5, Grok 3, and all other Popular AI writing tools.

• Mixed editing

It gives a clear percentage score and highlights suspicious parts.

So… Which Detector Should You Use?

It depends on which AI tool you used or want to check against.

• Use Copyleaks if you suspect the content came from GPT, Claude, or Gemini.

• Use Grammarly for simple writing and fast checking.

• Use GPTZero for academic-style writing.

• Use Originality.ai if you’re a blogger or content writer.

No tool is perfect; There are chances for all detectors to give false positives. So the safest method is to check using 2 or 3 different detectors and compare the results.