Does Grammarly Humanize AI Text? (No, and Here Is Why)

Grammarly is a grammar checker, not a humanizer

Grammarly does three things well: it checks grammar, suggests clearer phrasing, and flags passive voice. What it does not do is change the statistical patterns that AI detectors look for.

We tested this

We ran a 1,500-word ChatGPT essay through Grammarly Premium's "Rewrite" feature, applied all suggestions, and submitted to GPTZero.

• Before Grammarly: 97% AI
• After Grammarly: 91% AI

Grammarly improved the grammar and readability but barely moved the AI detection needle. That is because it is designed to make writing correct, not to make it statistically unpredictable.

What Grammarly actually does with AI text

Grammarly can detect AI-generated text (they added this feature in 2024), but it cannot fix it. It tells you "this paragraph may be AI-generated" without offering a way to address the detection.

Think of it this way: Grammarly is the doctor that diagnoses the problem. A humanizer is the treatment.

What to use instead

If you need to humanize AI text, use a purpose-built tool. Humanize AI Pro is free and specifically designed to restructure text so it passes detectors. You can use Grammarly afterward to catch any grammar issues in the humanized output — the two tools complement each other but do different jobs.

The combination approach

1. Generate text with ChatGPT
2. Humanize with Humanize AI Pro
3. Polish with Grammarly

This gives you text that passes detection, reads naturally, and is grammatically clean.