Skip to content
DetectGPTCheck

Turnitin® AI Detector Alternative

Free AI detectorby DetectGPT

Advanced AI Content Detector for ChatGPT, GPT-5 & Other LLMs

Check if your text is AI. If you came for a Turnitin® detector, this is a free self-check you can open without a school login. Paste a draft or a page URL, get a score.

  • 3,000 words
  • No account
  • Any LLM draft
  • Analyze URL
  • Ridiculously fast

Draft

Try an example:
0 / 3,000 words

AI writing report

0%

Waiting on a draft

Flagged passages come back light yellow over 20%, then yellow, orange, or red.

Independent detector. Not affiliated with Turnitin®, and not their software.

Why Choose DetectGPT for AI Detection

DetectGPT reads the words you paste without a login, a campus license, or the original prompt. Drop in text from any model, or text you wrote yourself, and see how machine it sounds.

  • 3,000 words per run

    Paste a full essay-length draft. Split anything longer and run it in chunks.

  • Paste text or a homepage URL

    Drop the words in the box, or analyze a public page without logging into the site.

  • Works on any LLM draft

    ChatGPT, Claude, Grok, Gemini, or something you wrote yourself. DetectGPT is the brand, not one model.

  • Report you can actually read

    A percentage plus yellow, orange, and red passages, so you can see which lines still sound like a model.

  • No account, no campus login

    Run it in a browser. Nobody at school has to share Feedback Studio with you.

  • Share a result link

    Send the report without making someone paste the draft again.

Quick reference

At a glance

Best for
Anyone who used a model and wants a look before someone else does
Checks
The finished draft, or a public URL. Not your ChatGPT, Claude, or Grok account
Time
Under a minute for 3,000 words
Cost
Free, no account
Unlimited words
Unlimited checks, no daily cap. 3,000 words per run
Word cap
3,000 words per run. Split longer pieces
URL scan
Homepages, articles, public posts. Not login walls or PDFs
Output
A percentage plus highlighted lines
Languages
Strongest on English
Proof of authorship?
No. Style, not a courtroom
Similarity check
Plagiarism Checker tab. Public web overlap, 3,000 words
Similarity score
A percentage plus matching phrases and source links

The tell

What DetectGPT actually looks at

Language models pick the next likely word, which leaves a fingerprint of even sentence length, generic transitions, and adjectives that never take a side. DetectGPT scores those habits on the finished draft only. It does not open your ChatGPT, Claude, or Grok account and never sees the prompt.

A tidy student essay and a lightly edited Claude memo can both trip it, because the question is not who typed this. It is whether the draft still sounds like a model.

The number

How to read the percentage

The number is a share of the prose that looks machine-made rather than a probability that you cheated. Forty percent means a chunk of the draft still sounds like a model, not a 40% chance of a misconduct case.

  • Under ~20%

    Weak signal. Lots of human writing lives here. Do not treat it as a pass.

  • 20% to 50%

    Mixed. Some lines drone. Read it out loud and rewrite the stiff bits.

  • Over 50%

    The draft still sounds like a model. Keep your facts. Change the voice.

Walkthrough

How to use DetectGPT

  1. 1

    Paste at least 50 words, or drop in a public URL including a homepage.

  2. 2

    Stay under 3,000 words, or split a longer piece.

  3. 3

    Hit Check AI score and wait for the report.

  4. 4

    Read the percentage, then the lines that lit up.

  5. 5

    Rewrite the stiff parts in your own voice and keep a copy of each version.

Also on DetectGPT

Similarity score check

DetectGPT also has a plagiarism checker. Open the Plagiarism Checker tab, paste up to 3,000 words, and it will look for matching phrases on public pages, then list the source next to each hit so you can see what overlapped instead of staring at a crayon.

If you needed a free plagiarism checker for students, use the Plagiarism Checker tab or open the free plagiarism checker: paste the draft, run the similarity score, and read the source list.

The similarity score is web overlap rather than an AI writing percentage or a campus originality report, so quoted facts and common textbook lines can light up without anyone copying an essay. Use it as a first look and read the sources before you treat the number as a verdict.

Audience

Who is DetectGPT for

  • Students

    A private pass over a paper before you hand it in, especially if you used a model for an outline or a first pass and cannot open a Turnitin® detector yourself.

  • Teachers and writers

    Catch the glue phrases that make a post sound generated before a client or editor does.

  • People writing in a second language

    Careful, even prose is a known false alarm, so use the score to vary rhythm instead of panicking.

Side by side

DetectGPT vs ZeroGPT vs Turnitin® Detector

Three checkers sit in the same family of AI-writing signals, but they are three different products and none of them reprint another’s number. DetectGPT is the self-check, ZeroGPT is another public dashboard, and Turnitin® Detector is the campus report most students never see until after they submit.

DetectGPTZeroGPTTurnitin® Detector
Who can use itAnyone in a browserAnyone in a browserSchool or publisher license
CostFreeFree tier, paid extrasWhatever the institution pays
School loginNoNoYes, through the LMS
Self-check before submitYesYesUsually no. Instructors see the report
AI writing scoreYes, on this pageYes, percent AI / GPTYes, AI writing indicator
Word cap3,000 per runVaries by planFull paper inside the assignment
Plagiarism indexNoNo (style only)Yes. That is the main product
Public similarity checkYes, web overlapNoCampus similarity report
What it readsFinished prose from any LLMFinished proseSubmitted files in Feedback Studio
Official campus toolNoNoYes
AffiliationIndependentIndependentTurnitin, LLC

Turnitin® is a registered trademark of Turnitin, LLC. DetectGPT is not affiliated with Turnitin® or ZeroGPT.

Limits

What DetectGPT cannot do

  • It cannot prove who wrote a sentence.

  • It cannot match a school’s private report one for one.

  • It cannot scan images, slides, or scanned PDFs. Paste the prose.

  • It cannot bless a draft against a syllabus. Policy still sits with you.

  • It cannot hit 0% on honest writing every time. Humans are not random either.

FAQs

What is a Turnitin AI detector?
It is the AI writing indicator on a campus report: a percentage for how much submitted prose looks like language-model output. DetectGPT is a separate checker you can run yourself. Same kind of job, not their software.
Can Turnitin detect AI?
Yes, as a style classifier on qualifying prose, not as a search of ChatGPT or Claude. It can miss edited drafts and it can flag careful human writing. Treat it as a signal, not a verdict.
What percent AI is acceptable?
There is no official cutoff. Scores under about 20% are noisy on most checkers. Your course or client policy is the real rule. Do not chase 0%.
How accurate is AI detection?
It is a usable signal and a weak judge. Short text, formulaic academic prose, and second-language writing produce more false alarms. Detectors also disagree with each other.
What is the best AI detection tool to run before I submit?
The one you can actually open. DetectGPT and ZeroGPT are public. Campus reports usually are not. No tool reprints another tool’s number. Rewrite the stiff lines either way.
Will DetectGPT match another AI score?
No. Checkers do not share one percentage. Use DetectGPT as a comparable style check, then edit. Do not screenshot one dashboard as proof against another.
Does DetectGPT only check ChatGPT?
No. DetectGPT is the brand. It scores writing from ChatGPT, Claude, Grok, Gemini, and other models. It never logs into those labs.
Is DetectGPT free?
Yes. No account, no card, 3,000 words per run. Paste text or analyze a public URL.
Can I analyze a URL or a homepage?
Yes. Use Analyze URL, paste a public page, including a homepage. We pull the readable text and score it. Login walls, PDFs, and apps will not work.
Does DetectGPT have a plagiarism checker?
Yes. Open the Plagiarism Checker tab, paste up to 3,000 words, and run a similarity score check. It looks for matching phrases on public web pages and lists source links. It is not a student paper archive and it will not reprint a campus similarity report.
What is the similarity score on DetectGPT?
It is the overlap percentage from the plagiarism checker: how much of the pasted draft matched public pages, plus the phrases and links. Cited facts and common textbook lines can score high. Open the sources before you treat the number as a verdict.
Do you keep the draft I paste?
Text you paste is scored in your browser. History stays on this device. If you analyze a URL, our servers fetch that public page so we can read it. Do not paste secrets.

Paste the draft

Paste up to 3,000 words as text or a homepage URL.

Read the score

A percentage for how machine the draft sounds.

Fix the voice

Rewrite the stiff lines and keep a copy.

The bottom line

Write the way you write, run the checker, and fix the lines that still sound generated while you keep a copy of each version.

DetectGPT will not make you a better writer, but it will show you where the draft still talks like a model, and that is the part worth fixing.

Try DetectGPT free today