Writing

Free AI Detector

Paste any text and see an AI-likelihood score plus sentence-level highlights. Free for about 1,200 words.

Choose a writing style before you run it. Long pieces can open in the editor, where you can export PDF, Word, Markdown, HTML, or plain text. Detection can be wrong: human writing is sometimes flagged. See all writing tools.

  • Free to use
  • No sign-up for your first runs
Detection can be wrong. Human writing is sometimes flagged (false positives), and edited AI text is sometimes missed. Use the score as a signal, not a final judgment.
Style:
Voice:

Usual. Leaves this tool's normal writing alone. Pick another style if you want a specific sound.

Style is not used for the score. It is sent along when you humanize this text.

0 / 1,200 words

AI likelihood

Your AI-likelihood score and highlighted sentences will appear here...

How the AI Detector Works

Get results in seconds with a simple workflow.

1

Paste your text

Add the passage you want to check. Free checks cover about 1,200 words.

2

Read the score

You get an overall AI likelihood and a highlight on each sentence.

3

Humanize if you want

Use Humanize this to open the AI Humanizer with the same text.

See It in Action

The same paragraph, scored. Highlights show which sentences contribute most to the AI likelihood.

Before

Artificial intelligence is transforming industries across the globe. Furthermore, these advancements underscore the importance of leveraging cutting-edge technologies.

After

72% AI likelihood. The second sentence is highlighted because of the generic transition and abstract claim. The result can still be wrong.

Why Use Our AI Detector?

Powered by the latest AI to deliver fast, accurate results.

One overall score

See a single AI-likelihood percentage, plus a plain-language read of what it means.

Sentence highlights

Sentences that look more AI-written are marked, so you can edit those lines first.

Honest about mistakes

Detection can flag human writing and miss edited AI text. The page says so up front.

Humanize in one click

Send the same text to the AI Humanizer when you want it to read more naturally.

Pro Tips for Better Results

Get the most out of the AI Detector with these expert tips.

Treat the score as a signal

A high score does not prove a model wrote the text. Formal human writing is often flagged.

Edit the highlighted lines

Start with the sentences marked as likely AI. Specific details and uneven rhythm usually help.

Check again after humanizing

Run the detector on the humanized draft. A lower score is still not a guarantee.

Do not use it as the only check

For school or editorial decisions, read the writing. The detector is one input, not a judge.

Who Is This For?

Trusted by millions of students, writers, and professionals worldwide.

Students checking a draft before they submit it
Editors reviewing a freelance or AI-assisted article
Writers seeing which sentences still sound robotic
Teachers getting a signal, not a verdict, on student work
Marketers reviewing campaign copy before it goes live
Anyone comparing a humanized draft with the original

Check text with an AI detector before you publish

An AI detector estimates how likely a passage was written by a language model. It is useful when you want a second look at a draft, a student's essay, or a post that should sound like a person.

This page is WritingTools.ai's AI detector. Paste the text, get one overall score, and see which sentences contribute most to that score.

Detection can be wrong. Human writing is sometimes flagged, and AI text that has been edited can look human. Treat the score as a signal, not a verdict.

What the score means

  • Under 35%: the text mostly reads as human-written.
  • 35% to 69%: mixed. Some sentences look generated and some do not.
  • 70% or higher: the draft has a lot of patterns common in AI writing.

Highlights follow the same scale. A violet mark means the sentence looks more AI-written. A light amber mark means mixed. Sentences with no highlight look more human.

How to use the AI detector

  1. Paste the passage. Free checks cover about 1,200 words. Longer text is part of Premium, the same plan as the rest of WritingTools.ai.
  2. Read the overall score, then the highlighted sentences.
  3. If you want the draft to sound more natural, use Humanize this to open the AI Humanizer with the same text.
  4. Run the detector again after you edit. A lower score is not a guarantee.

What this AI detector does not do

  • It does not prove who wrote the text.
  • It is not a plagiarism checker.
  • It should not be the only reason to reject a student's work or a writer's draft.

If you need a rewrite rather than a score, start with the AI humanizer or the paraphrasing tool, then fix grammar with the grammar checker. For the wider set of writing tools, go back to WritingTools.ai.

A practical note on false positives

Short, formal, or highly edited sentences are easier to misread. A polished abstract, a legal clause, or a list of instructions can score higher than a casual email even when a person wrote it. When the score surprises you, read the highlighted sentences and decide whether they actually sound off.

Premium checks longer documents on the same plan. There is no separate detector plan.

Comparing tools?How AI detection worksQuillBot alternative

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Frequently Asked Questions

Yes. Free checks cover about 1,200 words. Longer text is part of the existing Premium plan.

Yes. Human writing is sometimes flagged, and AI text that has been edited can look human. Use the score as a signal, not a final judgment.

No. A low score means the text has fewer patterns common in AI writing. It is not proof of authorship.

Use Humanize this on the result. It opens the AI Humanizer with the same text so you can rewrite it, then check again. A lower score is still not proof a person wrote it.

Yes. Open the text in the writing editor, keep the wording, then export or publish it. Detection highlights are not saved with the document.

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  • Styles and saved voices
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Do it all in one document

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Free AI Detector (Check AI-Written Text) | WritingTools.ai