AI Text Detector
Shows the actual stylistic signals — sentence rhythm, formulaic phrases, word variety — never a fake confidence percentage.
Also known as: AI content detector, ChatGPT detector, AI writing checker, AI-generated text checker
How it works
- 1Paste at least a paragraph or two (40+ words) of the text you want to check.
- 2Everything is analyzed instantly, locally in your browser — nothing is ever sent anywhere.
- 3Review each of the five signals individually — the number, whether it crossed a threshold, and its specific caveat.
- 4Check the matched-phrases list to see exactly which words and phrases were found, not just a count.
Why use AI Text Detector
No fake confidence percentage
Never collapses multiple weak signals into one misleading number — every check is shown individually, with its own measurement.
Every signal shows its work
See the actual sentence-length variation, vocabulary-variety score, and phrase-density numbers — not just a verdict.
Matched phrases shown, not hidden
The exact AI-associated words and phrases found in your text are listed with their counts, so you can judge for yourself.
Every signal has a stated caveat
Each check explicitly states what it can't tell you — including known false-positive risks for formal or non-native writing.
Nothing ever leaves your browser
The entire analysis runs as plain JavaScript in the page itself — no server call, ever.
Free, unlimited, no account
Check as much text as you want, with no daily cap and nothing to sign up for.
Who uses AI Text Detector
A second opinion before accusing someone
Use this as one honest input — never a verdict — before raising a concern about a student's or colleague's writing.
Checking your own AI-assisted drafts
See which stylistic patterns your own writing (or a heavily AI-edited draft) carries before publishing it.
Spotting formulaic phrasing in content marketing
Catch overused AI-associated phrases like "delve into" or "in today's fast-paced world" before they ship.
Understanding what detectors actually look at
See the real, disclosed signals behind AI-detection claims instead of trusting an opaque score from another tool.
A sanity check on suspiciously uniform writing
Check unusually even sentence and paragraph rhythm in a document that reads a little too polished.
About AI Text Detector
The AI-detection industry has a trust problem, and it's not a minor one. Independent testing has repeatedly found detector accuracy far below vendor claims: real-world university testing found GPTZero incorrectly flagged 15% of genuinely human-written essays; Turnitin's claimed under-1%-false-positive rate turned out closer to 4% at the sentence level in independent testing, with non-native English writers flagged up to 30% more often than native speakers; an independent test of Originality.ai found 76% overall accuracy and flagged a real, years-old human blog post as 61% AI-generated. Vanderbilt University disabled Turnitin's AI detector entirely in 2023 after calculating that even the vendor's own claimed 1% false-positive rate would still wrongly accuse roughly 750 students a year.
That's the backdrop this tool was built against. Rather than adding one more black-box percentage to a category people already have good reason to distrust, this measures a specific, disclosed set of stylistic patterns and shows the actual numbers behind each one: how much sentence length varies across the text, how varied the vocabulary is, how often a curated list of AI-associated words and phrases ("delve into," "it's important to note," "furthermore," "seamlessly") shows up per 1,000 words, how often em dashes appear, and how evenly sized the paragraphs are. Every one of these is independently checkable — nothing is hidden behind a model's internal weights.
Text has no equivalent to a photo's embedded metadata — there's no widely-adopted, checkable record of "this paragraph was written by an AI model" the way C2PA Content Credentials work for images. That's an important, honest limitation, not a detail to gloss over: this tool cannot do what the AI Image Detector does. What it can do is measure real, present-in-the-text patterns and disclose exactly what it found, with the specific matched phrases shown alongside each score, so nothing is asserted that isn't directly checkable in the text itself.
None of these five signals means anything reliably on its own. A technical writer, a non-native English speaker, someone who writes in a formal register, or anyone who simply favors em dashes will trip several of these checks without an AI ever being involved — which is exactly why this tool never collapses them into a single score, and why every signal ships with its own explicit caveat about what it can't tell you.
AI Text Detector vs. other options
How Open Tools Library compares to desktop software and other online tools.
| Feature | Open Tools Library | Desktop software | Other online tools |
|---|---|---|---|
| Method | Five disclosed stylometric checks, shown individually | Varies | Usually a black-box model with a single score |
| Confidence percentage | Never shown — considered misleading | Varies | Almost always shown, despite documented inaccuracy |
| Shows exactly what was matched | Yes — every phrase and count listed | Rarely | Rarely |
| Text privacy | Never uploaded | Stays local | Uploaded to a server |
| Price | Free, unlimited | Often paid | Often a paid tier or capped free checks |
Pro tips
- Treat every result here as a hint worth a second look, not proof — that's true of every AI text detector, not just this one.
- A formal, technical, or academic writing style will naturally trip several of these signals with zero AI involvement — context matters more than any single score.
- Non-native English writers are documented to be flagged more often by AI detectors generally; weigh that risk heavily before treating any result as an accusation.
- Short text (under about 40 words) doesn't carry enough signal to measure reliably — the tool will tell you plainly when that's the case rather than guessing anyway.
- The matched-phrases list is the most concrete, checkable part of the report — read the actual phrases, not just the count.
- If a result matters for a real decision, use it alongside your own judgment and direct conversation, not as a stand-alone verdict.
Technical specs
- Signals checked
- Sentence-length variation, vocabulary variety, AI-associated phrases, em dash frequency, paragraph uniformity
- Language model used
- None — pure statistical/stylometric analysis
- Confidence percentage shown
- Never — each signal reports its own measurement
- Minimum text length
- 40 words for a baseline check; some signals need more
- Processing location
- 100% local, in your browser
Privacy & security
Checking a piece of writing for AI signals usually means pasting it into yet another server you don't control — which matters more, not less, for text you're not sure about sharing.
Every check runs locally in your browser tab — your text is never sent to a server, not even for analytics.
No account, login, or email address is required to use any part of this tool.
Nothing about the text or the result is stored anywhere once you close the tab.
Equally private whether you're checking one paragraph or an entire document.
Frequently asked questions
Is my text uploaded anywhere?
No. Every check runs as plain JavaScript in your browser tab — your text is never sent to a server, not even for analytics.
Does this use an AI model to detect AI text?
No. It measures five disclosed statistical patterns — sentence rhythm, vocabulary variety, phrase frequency, punctuation, and paragraph structure — using plain code, not a trained classifier.
Can this reliably catch AI-generated text?
No — and no tool honestly can, including paid ones with far more resources behind them. This tool is built around that limitation instead of hiding it, which is why it shows disclosed signals instead of a fabricated verdict.
Is it biased against non-native English writers?
Every AI-detection approach, including this one, risks flagging formal or non-native writing styles more often — that's a documented, industry-wide problem, not something unique to this tool. It's stated explicitly in every signal's caveat rather than left for you to discover the hard way.
What's the minimum amount of text I need?
About 40 words for a baseline check; some individual signals (like sentence-length variation, which needs at least 5 sentences) require more text before they'll report a result at all.
Troubleshooting
Why won't this tool just give me a percentage like other AI detectors?
Because that percentage would be manufactured confidence a five-signal stylometric check can't actually back up — and independent testing has repeatedly shown other detectors' percentages are far less reliable than they claim. Showing each signal's real number is the more honest option.
It found several signals — does that mean the text is AI-generated?
No. Every signal here also shows up in plenty of genuinely human writing — a formal register, technical writing, or a non-native English writer's style can trip several checks with no AI involved. Treat multiple signals as worth a closer look, not as proof.
It found no signals — does that mean the text is definitely human-written?
Not necessarily. A heavily-edited or unusually plain piece of AI text can avoid these patterns entirely. Absence of these five specific signals isn't the same as confirmation of human authorship.
Why does it say my text isn't long enough to check?
Several signals — especially sentence-length variation and vocabulary variety — need enough words and sentences to produce a statistically meaningful number. Below that, the tool says so plainly rather than reporting a misleading result from too little data.
Related searches
Landed here looking for something worded a little differently? AI Text Detector covers all of these too:
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