Free AI Detector

How AI Detection Works

AI writing leaves a statistical fingerprint. Language models pick the most probable next word, so their output has unusually low perplexity (predictable word choices) and low burstiness (uniform sentence length). Human writing bounces around: fragments, varied rhythm, occasional contradictions, imperfect punctuation. Detectors look for the absence of that mess.

This free AI detector takes a different approach from pure statistical classifiers. It sends your text to an AI model tuned to identify the specific markers detectors flag: formulaic transitions, repetitive sentence openers, AI-favorite vocabulary, hedged "on the other hand" balance, and generic examples. You get a 0-100 AI likelihood score plus the exact markers found, so the result is explainable instead of a black-box number.

How to Read Your Score

Scores of 0-20 mean the text reads as almost certainly human. Scores of 21-40 suggest a human writer with some AI-like habits, which is common in formal or academic prose. The 41-60 band is genuinely ambiguous and deserves a human read, not a verdict. Scores of 61-80 indicate likely AI generation, and 81-100 means the text is saturated with machine patterns.

Length matters more than most people expect. Under about 100 words, every detector struggles, because there is not enough text for patterns to emerge. Past 200 words, accuracy climbs sharply. If you are checking a short paragraph, treat any score as a weak signal.

What This Detector Catches

The markers this tool reports map directly to what institutional detectors like Turnitin and GPTZero weight most heavily: sentences that all start the same way, transition words such as "furthermore" and "moreover" doing structural work a human would do with rhythm, compulsive contraction expansion ("do not" where a person would write "don't"), surgically clean punctuation with no fragments, and vocabulary tics like "leverage," "delve," "comprehensive," and "utilize."

It also flags the subtler tells: writing with no personal voice, arguments that hedge every claim into neutrality, and examples so generic they could illustrate anything. These are the patterns that survive paraphrasing, which is why word-level rewrites often still get flagged.

Who Uses an AI Detector

Teachers and professors use AI detectors to screen student work before academic-integrity conversations. Editors run freelance submissions through them before paying for "original" writing. Hiring managers check cover letters that read suspiciously polished. And writers themselves use this tool as a self-check: paste a draft, see what gets flagged, and revise before submitting somewhere that runs Turnitin or Originality.ai.

If your own text scores high, that does not mean you cheated. It means your writing shares patterns with machine output. The fix is usually concrete: vary your sentence lengths, cut the transition words, add contractions, and put one specific detail where a generic phrase sits. Or run it through our AI Humanizer, which rewrites those exact patterns while keeping your meaning.

The Limits of AI Detection

No AI detector is a lie detector, including this one. Short texts misfire. Heavily edited AI text can pass. Formal, non-native, or highly structured human writing can fail. Detection models also decay: as language models change, the patterns shift, and every detector needs retraining to keep up.

Treat any score as a signal that deserves a human read, never as proof of anything. If you are making a consequential decision about someone else's work based on a detector score, you are misusing the tool.

Frequently Asked Questions