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Was this text written by AI?Check ChatGPT, Claude, Gemini, DeepSeek & more

Paste any essay, article, email or report and see whether it was generated by an AI model — ChatGPT (GPT-5, GPT-4o), Claude (Opus 4.8, Sonnet 4.6), Gemini, DeepSeek, Grok, Llama or Mistral. Get an AI-likelihood score in seconds, with a per-sentence breakdown on Pro.

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SEE IT IN ACTION

An AI score you can actually read

Every scan returns a clear AI-likelihood score and a sentence-by-sentence breakdown — so you can see exactly which lines look AI-generated, not just a single number.

  • An overall AI-likelihood gauge with a plain-language verdict.
  • Per-sentence highlighting that flags the specific lines to review.
  • A "why this score" view of the signals behind the result.
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The TextSight AI Detector result panel: an overall AI-likelihood score shown on a gauge, with sentence-by-sentence analysis highlighting which lines read as AI-generated.
DEFINITION

What is an AI content detector?

An AI content detector is a tool that estimates how likely a piece of writing was produced by an AI model — such as ChatGPT, Claude or Gemini — rather than by a person.

It works by reading the statistical fingerprint of the text: how predictable the word choices are, how much sentence length and rhythm vary, and how closely the structure follows the smooth, even patterns that language models tend to produce. From those signals it returns an AI-likelihood score — usually a percentage — rather than a simple yes or no.

An AI detector is not the same as a plagiarism checker. A plagiarism checker compares your text against existing published sources to find copied passages; an AI detector looks at how the text was written to estimate whether a machine generated it, even when every sentence is original. Many writers use both — one to confirm originality, the other to confirm human authorship.

DO THEY WORK?

Do AI detectors actually work?

Yes — but with real limits, and the honest answer is more useful than a marketing one.

50%+
In a widely cited 2023 Stanford study, several popular AI detectors wrongly flagged more than half of the essays written by non-native English speakers as AI-generated.Liang et al., Stanford University, 2023

On clear cases — a few hundred words of unedited AI text in English — a good detector is reliably accurate. The hard cases are short snippets, heavily edited or paraphrased text, and writing by non-native English speakers, whose more measured, template-like style can resemble AI.

That is exactly why TextSight reports a probability with a sentence-level breakdown instead of a guilty verdict, and why we are upfront that detection is tuned for English. Used as one signal alongside drafts, version history and a conversation with the writer, AI detection is genuinely useful. Used as sole proof of cheating, no detector on the market — including ours — is reliable enough.

COVERAGE

Which AI models it detects

TextSight analyzes writing patterns shared across the major large-language-model families — not just one vendor — so it generalizes across the current frontier of AI text generators. That means you can check output from a brand-new model the day it launches and still get a meaningful read, because the detector keys on how AI writes rather than memorizing one system.

OpenAI
ChatGPT · GPT-5 · GPT-4o · GPT-4
Anthropic
Claude Opus 4.8 · Sonnet 4.6 · Haiku
Google
Gemini 3 Pro · Gemini 2.5 · Flash
xAI
Grok 4 · Grok 3
DeepSeek
DeepSeek V3 · R1 · and newer
Meta
Llama 4 · Llama 3.3
Mistral
Mistral Large · Mixtral
Open-source
Qwen · plus most fine-tuned variants

The signals are model-agnostic, so newer and unreleased models still produce a useful estimate. Heavily edited or mixed human-and-AI passages are inherently ambiguous — treat the score as strong evidence to review, not absolute proof.

WHO USES IT

When you need to know if text is AI

AI writing now turns up everywhere — student essays, job applications, emails, articles and filings. A fast verification step protects trust and quality.

Educators & academic teams

Check student essays, theses, application materials and discussion posts before grading.

HR & recruiters

Verify cover letters, take-home assignments and written interview answers from candidates.

Editors & publishers

Screen guest posts, op-eds, press releases and freelance submissions for undisclosed AI use.

Marketing & content teams

Audit agency deliverables, freelance copy and contributor articles to keep brand voice authentic.

Legal & compliance teams

Review contracts, statements, policy documents and submissions before they are relied on.

Anyone with a suspicious message

Get a quick second opinion on an email, message or document before you act on it.

SEO & content writers

Check briefs, drafts and freelancer deliverables before they publish, so the content that ships reads as original human writing.

Researchers & academic writers

Verify literature reviews, drafts and contributor sections, and keep submitted work demonstrably your own.

WHAT WE ANALYZE

The signals of AI-written text

Every AI model leaves the same broad trace: writing that is fluent but unusually even. Before it returns a score, the detector breaks your text into the specific, measurable signals below, then weighs them together rather than leaning on any single tell.

Phrasing & predictability

AI writing leans on predictable word choices and smooth, low-surprise phrasing that reads evenly across a whole passage.

Sentence rhythm

Human writing varies in cadence and length. Uniform sentence rhythm and balanced structure are common signals of generated text.

Per-sentence highlights PRO

The free check returns an overall AI likelihood score; Pro and the app add per-sentence highlighting, exportable reports and unlimited daily scans.

HOW IT WORKS

How AI detection actually works

Human writing carries a particular irregularity — the pace shifts, sentence lengths vary and word choices surprise. AI-generated text is smoother and more even-paced, because language models optimize for the most probable next word. The detector measures that difference across several dimensions:

The score combines these into a single AI-likelihood estimate, with per-sentence highlighting on Pro showing exactly which lines triggered the model.

Three steps to use it

1

Paste your text

Drop in an essay, article, assignment, report or email. No sign-up needed to run your first checks.

2

Run the detector

Your text is analyzed with the same model as the full TextSight app for AI-generation signals.

3

Read the estimate

Get an overall AI-likelihood score and a plain-language verdict you can use as a prompt for review.

WHAT COUNTS

What counts as AI-written text?

The line between "AI" and "human" is rarely clean. Most real-world writing sits somewhere on a spectrum, and the detector scores accordingly instead of forcing a yes-or-no verdict.

Human voiceMixed / editedPure AI

The detector returns an overall likelihood score and, on Pro, per-sentence highlights — so you can pinpoint which lines look AI-generated even when a document reads human overall. That makes it especially useful on mixed-authorship work.

ACCURACY

Accuracy and limitations — what to expect

No AI detector is 100% accurate, and TextSight is no exception. The score is an estimate, not a verdict — a signal for closer review rather than proof of authorship.

For high-stakes decisions — academic integrity, hiring, publication — always pair the result with human judgment and a conversation with the writer.

COMPARISON

How TextSight compares to other AI detectors

The detection category is crowded, and the right tool depends on your use case. Here is where TextSight fits.

Where TextSight stands out: it pairs detection with a readable signal breakdown and per-sentence highlighting on Pro, so you get more than a verdict — you get the reasoning behind it. As with every detector, treat results as evidence to review, not proof.

LANGUAGES

Which languages it supports

TextSight's AI detection is built and tuned for English. That is where it is accurate and where we recommend relying on it.

Need other languages? TextSight's writing tools — the humanizer, summarizer and translator — support 50+ languages. AI detection, specifically, is English-first by design.

PRIVACY

Privacy and data handling

Your text stays yours. Here is exactly what happens to it.

USING RESULTS

How to read your AI score

The score is a starting point for a decision, not the decision itself. A few habits make it far more reliable.

Used this way, the detector becomes a fast triage tool — it tells you where to look, so you spend your attention on the passages that actually need it.

AI WRITING SIGNS

Common signs text was written by AI

No single phrase proves anything on its own, but a few patterns show up again and again in AI-generated writing. Once you know them, you can spot likely AI text before you even run a check.

These are hints, not proof — plenty of careful human writing shares some of them. The detector exists precisely because eyeballing alone is unreliable: it weighs many signals at once instead of one or two giveaways.

FALSE POSITIVES

What to do if your writing is wrongly flagged

Detectors sometimes flag genuinely human writing — especially short, formal or non-native English text. If that happens to you, a score is not a verdict, and you have ways to show your work.

We are deliberate about this: TextSight reports an AI-likelihood estimate, never a guilty verdict. For any high-stakes decision, the score should support human judgment, not replace it.

Verify authenticity at scale?

Open the full Detector in the app for per-sentence highlights, exportable reports, bulk scanning and unlimited daily scans.

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FAQ

AI detector questions

How does the AI detector work?
It runs your text through the same detection model as the full TextSight app, weighing linguistic signals that correlate with AI-generated writing — predictability, sentence rhythm, word choice and structural uniformity — to estimate an overall AI likelihood score.
Which AI models can it detect?
It estimates AI likelihood for text from ChatGPT (GPT-5, GPT-4o, GPT-4), Claude Opus 4.8 and Sonnet 4.6, Gemini, DeepSeek, Grok, Llama, Mistral and other large language models. The signals are model-agnostic, so newer or unreleased models still produce a useful estimate.
Can it detect GPT-5 and Claude Opus 4.8 text?
Yes. The detector is built around patterns shared by current frontier models — including GPT-5, Claude Opus 4.8, Gemini, DeepSeek and Grok — rather than one fixed model. Because those signals are model-agnostic, even newer or unreleased models still produce a useful estimate.
How accurate is it?
No AI detector is 100% accurate. Short, heavily edited or mixed human-and-AI passages are inherently ambiguous. Treat the score as an estimate of AI likelihood and a prompt for review — not as proof of authorship.
Can it detect mixed human-and-AI writing?
This is where per-sentence highlighting (Pro) helps most. The overall score gives you a single estimate, while the breakdown shows which specific sentences read as AI-generated versus human — so you can spot edited or partially-AI documents instead of getting a single yes/no.
Does it work for languages other than English?
The detector is trained and tuned on English, so English is where it is most reliable. You can paste text in other languages, but treat non-English results as directional rather than definitive. TextSight's writing tools — humanizer, summarizer and translator — support many more languages than detection does.
How is TextSight different from GPTZero, Originality.AI or Copyleaks?
Most detectors return a single verdict. TextSight shows the signals behind the score — predictability, sentence rhythm and variation — plus per-sentence highlighting on Pro, so you can see why a passage scored the way it did rather than trusting a bare number. No detector is perfect, so we present results as evidence to review, not proof.
Can teachers and professors detect ChatGPT?
Often yes — many schools run submissions through detectors such as Turnitin, and experienced instructors also notice sudden shifts in style or vocabulary. But a detector flags work for review; it is not proof on its own. Fair academic processes pair the score with your drafts, your writing history and a conversation about how the work was produced.
Do AI detectors work on paraphrased or "humanized" text?
Partly. Light paraphrasing and "humanizer" tools are designed to lower detector scores, and they can move the number. Robust detectors still catch a lot of reworked text, but heavily edited writing becomes genuinely ambiguous — which is also why a low score is never proof that a human wrote something. We treat the result as evidence, not a guarantee.
Will Grammarly or spell-check make my writing look AI-generated?
Fixing grammar or spelling on your own writing should not, by itself, make it read as AI-generated. The difference is scale: correcting mistakes keeps your voice, while letting a tool rewrite whole sentences makes the text smoother and more template-like — which is the pattern detectors react to.
How much can I check for free?
You can start with no sign-up. A free account raises your daily checks and word limit, and Pro adds unlimited daily scans, per-sentence highlighting, exportable reports and bulk scanning.
Is my text stored?
Not signed in? Your text is deleted right after the scan and never stored. Signed in, your scans save to your private history (deletable anytime). We never use your text for training.
Does it work on mobile?
Yes — the editor and results stack cleanly on phones.
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