Paste your text below (minimum 50 words, 100+ recommended) 👇
⚡ Instant
Results in seconds.
🎯 Accurate
Powered by Earlybird AI model.
🔒 Private
We don't store your text.
Paste AI text — we'll make it human, SEO-optimized & duplicate-free 👇
🧑 Human Tone
Varied sentences, contractions, natural flow.
🔎 Duplicate Check
Uniqueness score shows how different it is.
📈 SEO Ready
Natural keyword insertion, no stuffing.
What is FS AI Detector?
FS AI Detector is a free online tool that analyzes text and estimates whether it was written by a human or generated by an AI model such as ChatGPT, Claude, or Gemini. It also includes a free AI-to-human converter that rewrites AI text into natural-sounding, SEO-friendly content.
Why Use FS AI Detector?
- Free, No Signup — No payment needed (fair-use rate limit applies).
- Modern AI Detection — Trained on GPT-4, Claude, Llama and Mistral text.
- Humanize + SEO — Convert AI content to human writing.
- Privacy First — We don't store your text.
- Fast Results — Usually a few seconds per check.
How It Works
When you paste text, it's sent securely to our Cloudflare backend, which calls the Earlybird model (hosted on our own Hugging Face Space) for detection and Workers AI for humanization. The model analyzes patterns like sentence structure, word choice, and repetition, then returns a probability score.
Frequently Asked Questions
Is FS AI Detector really free?
Yes. It's free with no signup (a fair-use rate limit applies).
How accurate is it?
The model's authors report about 96% accuracy on 100–300 word texts and about 89% overall; very short texts (under 100 words) are far less reliable. It's an estimate, not proof.
Do you store my text?
We don't store your text. It's sent to our detection service to get a score and isn't saved by us.