Our AI Detector By Originality.ai™, available for free below, is the Most Accurate AI Detector for GPT-5, ChatGPT, Claude 4, Gemini 2.5, Grok 3 and all other Popular AI writing tools.
Trusted by Industry Leaders


























A complete suite of QA/QC products
AI Detector By Originality.ai™ offers a complete suite of patented AI tools for writers, students, editors, marketers, web publishers, and educators including, AI detection, Plagiarism Checking, Fact Checking & Grammar Checking.
Deep Scan ›
See why text is flagged as AI + how to ethically edit it, so your work is identified as original
(not AI)!
AI Checker ›
Most Accurate AI Detector for all AI writing tools. Try now for free.
Plagiarism Checker ›
See if text has been plagiarized from anywhere on the internet.
Content Optimizer ›
AI-powered content optimization that helps your content predictably rank better in Google.
Readability Checker ›
Optimize readability for your target audience to communicate clearly.
Bulk Scan ›
Scale content QA and scan an entire website’s content easily.
Grammar Checker ›
Say goodbye to typos. Catch grammar and spelling errors before you publish.
Fact Checker ›
Use our fact checking aid to help ensure your content is factually correct.

Step 1
Paste or Upload Text
Login to Originality.ai and paste your text into the editor. You may also upload a PDF to check if a document was written by AI or enter a URL for scanning.

Step 2
Select Scan Types
Select your desired scan types like AI, Plagiarism, Content Optimization, Readability, Grammar OR Fact Checker to scan your text against.

Step 3
Click Scan
Click on the Scan button and get scores for each scan type with detailed explanations and sentence highlights wherever applicable.
Originality.ai identified As The Most Accurate AI Detector Across Multiple Studies
Study
Results Shown
Accuracy comparison of AI text detection tools on AH&AITD
Percentage correct for GPT-4 papers
Mean accuracy at FPR=5% for detectors on non-adversarial outputs
Mean accuracy for ChatGPT-generated and AI rephrased articles
Mean AUROC of GPT-3.5 vs. human-written, GPT-4 vs. human-written, mixed human/GPT-3.5 vs. human-written, mixed human/GPT-4 vs. human-written, translated vs, human-written
Mean accuracy for (a) human vs. AI and (b) human vs. disguised
Originaltiy.ai
97.09
100
85
100
87.9
86.5
GPTZero
63.77
57
67
45
77.28
84.5
Writer
69.05
40
Not included
Not included
Not included
Not included
CopyLeaks
Not included
100
Not included
Not included
Not included
Not included
TurnItIn
Not included
100
Not included
62
Not included
Not included
Binoculars
Not included
Not included
80
Not included
Not included
Not included
FastDetectGPT
Not included
Not included
74
Not included
Not included
Not included
ZeroGPT
Not included
83
66
92
Not included
85
GPT-2 Output Detector
Not included
Not included
Not included
85
Not included
Not included
Sapling
66.66
33
Not included
Not included
75.92
Not included
Winston
Not included
Not included
71
Not included
Not included
77
GPTkit
55.29
Not included
Not included
Not included
Not included
Not included
Zylalab
68.23
Not included
Not included
Not included
Not included
Not included
SEO.ai
Not included
83
Not included
Not included
Not included
Not included
Scribbr
Not included
69
Not included
Not included
Not included
Not included
Grammica
Not included
62
Not included
Not included
Not included
Not included
Crossplag
Not included
69
Not included
Not included
Not included
Not included
OpenAI
Not included
40
Not included
Not included
Not included
Not included
IvyPanda
Not included
40
Not included
Not included
Not included
Not included
GPTRadar
Not included
31
71
Not included
Not included
Not included
Content at Scale
Not included
52
Not included
50
Not included
Not included
ContentDetector.ai
Not included
7
Not included
Not included
Not included
Not included
GLTR
Not included
Not included
63
Not included
Not included
Not included
RoBERTa-Base (GPT2)
Not included
Not included
59
Not included
Not included
Not included
RoBERTa-Large (GPT2)
Not included
Not included
57
Not included
Not included
Not included
RoBERTa-Base (ChatGPT)
Not included
Not included
45
Not included
Not included
Not included
LLMDet
Not included
Not included
35
Not included
Not included
Not included

Quick scan
Check for AI Content on Any Website Quickly
With our Chrome Extension you can check any webpage you are visiting to see if it is AI written text.

Easy copy paste
Quickly Check Content Using our Copy/Paste Window
Easy-to-use copy and paste text window: check content in Google Docs or any web page in Chrome to check for AI or plagiarism.

Identify Copy Paste
Watch a Writer Write
Peace of mind for writers and students. Watch a writer write the entire document with a sped up behind the scenes look and shareable report.
What Is the Best AI Detector Model for Your Needs?
The use of AI in content writing is nuanced. We have models that are tuned to your specific use case. Whether you allow AI editing or want NO AI to get past your review we have a model that is optimized for your approach to AI text detection.

For Writers & Editors
Lite 1.0.2
When you allow AI editing (think grammarly)

For Students & Teachers
Academic
Best for education use cases

For Professionals
Turbo
Zero tolerance policy on use of AI

For Non-English Texts
Multi Language
Optimized for 30 Languages

Factual Accuracy

Plagiarism Checking

Readability & Grammar Checking

Marketers, Writers & Publishers

Teachers & Students

Agencies & Enterprise
Is the Originality.ai AI detector free?
Is Originality.ai free, or is there a free Originality trial? We don’t offer a free trial of Originality.ai. Instead, we offer a limited free AI detection tool, with 3 free daily scans.
What Can Cause False Positives?
Tools that use AI to rewrite or edit copy (e.g., some Grammarly features) can cause false positives. Shorter text may impact accuracy; we have a 100-word minimum at Originality.ai.
Classic Model: An AI detection score of 60% Likely Original and 40% Likely AI is not a false positive. It correctly predicted with 60% confidence that your content was Likely Original.
AI Allowance scans (new): Align how much AI you allow with project guidelines.
How Can I Show My Work or Assignment is Original?
An AI score shouldn’t be used alone for academic integrity discipline.
Students and Writers: Share accuracy studies and show your writing process with our Chrome Extension.
Can I See Previous Scans?
Yes, scan history is stored for later retrieval or sharing. Complete removal of your account and data is available upon request.
What Languages Does Originality.ai AI Detection Support?
With Originality.ai, you can check if text is written by AI in 30 languages, with an overall accuracy of 97.8% for our multilingual model. Multilingual AI Accuracy Study.
Do Credits Expire?
Yes, per our Terms and Conditions, credits expire 2 years from the date of purchase.
How many free AI scans are there?
Check up to 2,000 words with the free AI checker, and run up to 3 free AI scans daily. To scan more words, upgrade to premium.
Do I need an account to run a free AI scan?
No, you can run up to 3 free AI scans daily without an account. To scan more words and run additional scans, you can conveniently sign up for Originality.ai.
Is my pasted text stored, shared, or used for training?
Text input into the free AI detector may be used for training. Users with an Originality.ai account can opt out of data use for AI training.
What does the AI score mean?
AI scores are predictions (probabilities) on whether text is AI-generated or Original (human-written). At Originality.ai, we emphasize that AI scores reflect probability, not guilt.
If you select AI Allowance, you choose how much AI you allow. So, your AI score reflects whether the percentage of AI writing is likely more or less than your selection.
Should an AI score be used on its own?
Use an AI score as one signal, not a final decision. Review other details like writing history and drafts before any high-consequence decisions. Always keep a human reviewer in the loop.
How does the Originality.ai AI detector work?
The Originality.ai AI Checker is based on a modified version of the BERT model and forms part of our patented all-in-one text analysis and verification system (U.S. Patent No. 12,253,988). For in-depth details on training, fine-tuning, and more, check out this blog post and this post to learn about our patented technology.
Does Originality.ai Detect AI Paraphrasing?
Originality.ai is accurate at detecting AI-paraphrased content (e.g., Quillbot). If you permit AI paraphrasing, adjust how much you allow with AI Allowance; read more in our accuracy study.
What Are AI Detection False Positives?
AI Detection false positives happen when human writing is incorrectly classified as AI-generated. At Originality.ai, we transparently share false positive rates in our accuracy study.
Note: False positive rates can vary by AI detection model and brand.