100% free · Runs 100% in your browser · No signup needed
Honest estimate: this tool analyzes writing patterns (sentence variety, repetition, predictability) to estimate AI likelihood. It is not a verdict — no detector is 100% accurate.
Paste text to analyze (minimum 50 words for a meaningful result)
AI likelihood score
0%
-Words
-Sentences
-Burstiness
-Repetition
Sentence highlights (red = more AI-like patterns, green = more human-like)
About AI Content Detector
What is the AI Content Detector?
The AI Content Detector is a free online tool that analyzes any piece of text and estimates how likely it was written by artificial intelligence versus a human author. Since tools like ChatGPT, Claude, and Gemini became mainstream, AI-generated writing has flooded classrooms, newsrooms, freelance marketplaces, and inboxes. Readers, teachers, editors, and hiring managers increasingly want to know whether the words in front of them came from a person or a machine — and this detector gives them a fast, honest first answer.
The detector works by examining linguistic patterns that tend to differ between human and machine writing. AI models produce text with unusually consistent sentence lengths (low "burstiness"), highly predictable word choices (low "perplexity"), generic transitions, and a polished-but-flat tone. Human writing, by contrast, is messier: sentence lengths vary, surprising word choices appear, and small imperfections slip in. Our tool scores these signals across your text and presents an overall AI-likelihood estimate, plus a sentence-by-sentence breakdown so you can see exactly which passages look machine-like.
Using it could not be simpler. Paste your text into the box — an essay, article, email, or cover letter — and click Analyze. Within seconds you get a clear percentage-style estimate, highlighted sentences color-coded by their individual scores, and a plain-English explanation of the patterns found. Everything runs entirely in your browser, so your text is never uploaded to a server or stored anywhere. And unlike many detectors that hide results behind paywalls, ours is completely free with no signup and no word-count games.
How to Use the AI Content Detector
Paste your text: Copy the text you want to check — an essay, blog draft, product description, or email — and paste it into the analysis box. The tool works best with at least 150 words; longer samples give more reliable pattern readings.
Click Analyze: Press the Analyze button. The detector scans sentence structure, vocabulary predictability, and stylistic signals across the whole passage.
Read the overall score: Your result appears as an AI-likelihood estimate (for example, "72% likely AI-generated"). Treat this as a probability signal, not a final verdict — more on that below.
Review sentence-level highlights: Sentences are highlighted by their individual scores, so you can spot exactly which passages look machine-written and which look human.
Check the pattern report: The tool explains which signals drove the score — uniform sentence length, repetitive phrasing, predictable transitions, and similar markers.
Decide your next step: Teachers might follow up with a conversation, editors might request revisions, and writers can use the feedback to add more natural variation to their own drafts.
Analyze another sample: Clear the box and run as many texts as you like. Every check is free, private, and unlimited.
Key Features
Overall AI-likelihood score: A single clear estimate of how likely the text is AI-generated, presented as an easy-to-read percentage.
Sentence-level analysis: Every sentence gets its own score and highlight color, revealing which specific passages look machine-written.
Pattern explanations: Plain-English notes on the detected signals — burstiness, perplexity, repetition, and transition style — so the score is never a black box.
Honest, caveated results: The tool clearly states it produces an estimate based on writing patterns, not a definitive verdict. No false certainty.
100% private: All analysis happens locally in your browser. Your text is never sent to a server, stored, or shared.
Works on any text: Essays, articles, emails, cover letters, product descriptions, social posts — if it is written in English, it can be analyzed.
Instant results: No queues, no accounts, no credits. Paste, click, and read your result in seconds.
Completely free: Unlimited checks with no signup, no trial period, and no locked "premium" scores.
Pro Tips
Use 150+ words: Very short texts do not contain enough pattern data. The longer the sample, the more meaningful the estimate.
Check suspicious passages separately: If only one section of a document looks off, analyze that section alone for a cleaner signal.
Compare against a known sample: Run a piece you know the author wrote by hand alongside the suspect text to calibrate your reading of the scores.
Remember the caveats: Formal or technical human writing can score as "AI-like," and heavily edited AI text can score as human. Use the result as a starting point, not proof.
Look at the sentences, not just the number: The highlighted breakdown often tells a richer story than the headline percentage.
Combine with other checks: Pair detection with a plagiarism scan and your own judgment for the fullest picture.
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Who Uses the AI Content Detector?
Teachers and professors: Screen essays and assignments for undisclosed AI use before grading, then follow up with students directly.
Editors and publishers: Vet freelance submissions and guest posts to protect editorial standards and originality.
Hiring managers: Check whether cover letters and writing samples reflect the candidate's real abilities.
Bloggers and site owners: Verify that paid content from freelancers is genuinely human-written before publishing.
Students: Self-check drafts to make sure their own writing voice comes through clearly.
Researchers: Quickly triage large volumes of text, such as survey responses, for likely machine-generated entries.
Frequently Asked Questions
How accurate is the AI Content Detector?
It is a useful screening tool, not a perfect judge. On longer texts (300+ words) with clear stylistic signals, heuristic detectors like this one are right more often than not. But accuracy drops on short texts, highly technical writing, or text that has been heavily edited. Always treat the score as an estimate.
Can the detector be wrong?
Yes. Formal human writing — legal documents, academic prose, technical manuals — can look "AI-like" because it is also uniform and predictable. Conversely, AI text that a person has rewritten can look human. False positives and false negatives are a known limitation of every AI detector on the market, including paid ones.
Does the tool store my text?
No. The analysis runs entirely in your browser using JavaScript. Your text is never uploaded to any server, never stored, and never shared with third parties. You can safely check sensitive or unpublished work.
How does the detection actually work?
The tool measures statistical patterns in writing: burstiness (how much sentence length varies), perplexity (how predictable word choices are), vocabulary repetition, and transition phrases. AI models tend to produce smooth, uniform, predictable prose; humans vary more. The score combines these signals into one estimate.
What text length works best?
Aim for at least 150 words, and 300 or more for the most reliable results. Very short passages — a tweet, a single paragraph — simply do not contain enough pattern data for a meaningful estimate.
Can AI-generated text be edited to fool the detector?
Often, yes. Rewriting sentences, varying their length, and adding personal details or quirks will lower any detector's AI score. That is exactly why results should be treated as one signal among several, never as proof.
Is it really free with no signup?
Yes. There are no accounts, no credit limits, and no premium tier hiding the "real" results. Paste text and analyze as many documents as you want.
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