Research-backed detection · 12 algorithms · 100% free

Free AI Text Detector
That Actually Works

Paste any essay, email, or story. Our detector checks it against 12 linguistic patterns from peer-reviewed research. Results in under a second — no account, no API key, no word limits.

🔍 GPT-4o & GPT-5 📖 Stories & fiction 🔒 Private — stays in browser ∞ No word limits ⚡ No login needed

AI Text Detector

Paste any text — instant results, no login required

Free Forever 🔒 Private
0 words — 30 minimum for reliable results
Try a sample:

Analyzing…

Narrative Academic
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Signal Breakdown tap to expand

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Accuracy note: Browser-based detectors achieve ~70–80% accuracy. Use as a screening tool, not sole evidence of AI use. How it works →

Detect Writing From Every Major AI

Updated for 2026 — every model that's actually being used right now

Why This Detector Is Different

Most AI detectors are a rip-off. This one isn't.

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Free Forever — For Real

Other detectors charge because they call the OpenAI API. We don't. The whole thing runs as JavaScript in your browser. Zero marginal cost = genuinely free for you. No plans, no tiers, no "you've used your 5 free checks today".

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Runs in Your Browser

Your text never leaves your device. We can't see it. We're not storing it. If you have confidential documents — student grades, legal drafts — that matters. Most detectors send everything to a third-party server. This one doesn't.

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Catches Story AI Too

GPTZero, Turnitin, Copyleaks — none of them catch AI romance novels or short stories. We have 6 algorithms specifically for narrative writing. They catch phrase loops, subject monotony, and semantic circularity that fiction AI can't help but produce.

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12 Algorithms, Not Just Vocabulary

Vocabulary detection is the easy part. We also check sentence burstiness, closing rituals, transition overuse, and 9 more signals — then combine them with a cluster boost. See the full methodology →

How It Works

Paste text. Hit analyze. Here's what happens between those two steps.

1
Paste Your Text

Minimum 30 words for reliable results. Longer texts score more accurately. No account, no file upload, no waiting.

2
12 Algorithms Run

Academic Mode and Narrative Mode run simultaneously. The engine picks the higher-confidence result. Each mode uses 6 specialized algorithms.

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Score + Full Breakdown

A score from 0–97% plus a breakdown of every signal that fired. See exactly what triggered the result, not just a number.

What AI Writing Actually Looks Like

Not bullet points — real text. See if you can tell before the score appears.

🤖 AI Wrote This — Score: ~89%
"In today's rapidly evolving landscape, it is crucial to note that this approach marks a pivotal moment. Furthermore, the intricate tapestry of considerations demands meticulous attention to every detail."

Four T1 vocab hits. Two transitions. One significance inflation.

✍️ Human Wrote This — Score: ~8%
"I've tried three different approaches and none of them worked. The second one came closest but broke something else in the process."

Specific, frustrated, first-person. No AI markers.

Real Scenarios Where This Helps

Questions People Actually Ask

Yes. It runs as JavaScript in your browser — every analysis costs us exactly nothing. No account, no credit card, no word limits. Google AdSense will eventually cover our hosting bill.
GPT-4o and GPT-5 still use vocabulary fingerprints identified in Kobak 2025 research — words like "delve", "meticulous", "tapestry" that spiked 3–28x after ChatGPT launched. We also check structural signals like sentence burstiness and closing rituals. More on ChatGPT detection →
Yes — this is where most detectors fail completely. Our narrative engine catches phrase loops, subject monotony, and semantic circularity that fiction AI can't avoid. What AI writing looks like in fiction →
Around 75–80% on clearly AI-generated text. Lower on humanized AI (30–60%). We're transparent about this — it's in the disclaimer on every result. Use it as one data point, not sole evidence. How accuracy is calculated →
No. The JavaScript runs locally in your browser. We have no database of submitted texts. Open your browser's network tab while running a check — you'll see zero requests going out.
Sometimes. Tools like Undetectable AI swap vocabulary specifically to defeat detectors. Our phrase loop and subject monotony signals often survive humanization because they operate at a structural level. Expect 30–60% detection on heavily humanized text. Humanized AI detector →
Research-Backed Detection: Our algorithms are based on peer-reviewed research including Kobak et al. "Delving into ChatGPT usage in academic writing through excess vocabulary" (Science Advances, 2025), Stanford HAI writing pattern studies, and the Wikipedia AI Cleanup Project. Read the full methodology →