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Ever read something that feels almost human, but not quite?
With AI tools like ChatGPT and DeepSeek churning out content at lightning speed these days, it’s getting tougher to tell what’s real and what’s not.
That’s where AI detectors come in. These tools are designed to analyze text and determine whether it was written by a human or produced by a machine.
But here’s the thing. There’s a ton of AI detectors out there. Seriously, do a quick Google search right now and you’ll see what I mean.
Honestly – who’s got the time to go through the hundreds of tools? But lucky for you, you found this handy dandy article!
I’ve put tons and tons and tons of AI detector to the test myself, running them against samples of 100% human writing (my own), as well as pure AI (DeepSeek and ChatGPT) output.
And based on the results of my (highly laborious) testing, I rounded up the 10 best performing AI detectors, which I’ll break down in this article.
What Are AI Detectors?
AI detectors are tools that analyze text to determine if it was written by a human or generated by an artificial intelligence model, like ChatGPT, Grok, or DeepSeek.
They’ve become super important as AI writing grows more common, helping people distinguish authentic content from machine-made stuff. So, whether you’re a teacher checking student work, a business ensuring your content feels human, or just curious about what you’re reading, these tools are here to help.
How Do AI Detectors Work?
So, how do AI detectors actually figure out what’s human and what’s not? They rely on smart technology trained on huge datasets – some human-written, some AI-generated – to spot the differences.
AI detectors look for patterns: AI writing often has consistent sentence lengths, predictable word choices, and a lack of the natural quirks humans add.
They measure things like “perplexity” (how unpredictable the text is) and “burstiness” (variety in sentence structure). If something reads too smooth or formulaic, it’s likely flagged as AI.
Some tools give you a percentage score, like “75% AI-generated,” while others point out specific sections they suspect.
They’re not flawless, though.
As AI gets better at mimicking humans, detectors can struggle, especially with edited or hybrid text. Still, the top ones shine when the lines are clear 🙂
OK, enough background information. Let’s get into the meat of this article: the 10 best AI detectors.
1. SurgeGraph – Best Free AI Detector
SurgeGraph offers a free AI detector that helps you figure out if a piece of text was written by a human or churned out by AI.
It’s built by a team with a decade of content writing experience, so they know a thing or two about what makes writing sound real.
Oh, and if your content gets flagged as AI, the free AI humanizer is right there to fix it up. Or, if you’re tired of tweaking, SurgeGraph’s Vertex AI writer can whip up content that’s already humanized to bypass AI detection, saving you the hassle of extra steps.
SurgeGraph’s AI Detector
Features
Detailed Analysis: You get a breakdown of your text with an AI vs. human score, plus each sentence is tagged as human or AI, so you know exactly what to tweak.
Long Text Scans: Unlike most detectors that cap out at 5,000-10,000 characters, this one handles up to 50,000 characters – great for longer pieces.
Advanced Tech: Their AI detection technology uses deep learning, NLP, neural networks, and large language models for highest accuracy.
Context-Smart Detection: It looks at how sentences connect to the bigger picture, not just isolated chunks, which helps catch sneaky AI text.
Format-Proof: Tweaking formatting won’t fool it; the algorithms dig deeper than surface tricks.
Scan History: You can revisit past scans anytime.
Free Humanizer: If your content gets flagged as AI, you can use their free AI humanizer to tweak it and bypass detection.
Vertex AI Writer Option: For faster results, their Vertex AI writer generates auto-humanized content that mimics your own style and skips AI detection without extra effort.
Sentence-Level AI Detection
Pricing
SurgeGraph’s AI detector is completely free – no hidden catches. You just paste your text, click a button, and you get your AI detection results.
It also offers a generous character limit for scanning at 50,000 characters, which is one of the highest in the industry, considering the completely free access.
2. Quillbot
Quillbot is an AI-powered writing assistant that launched in 2017, focusing primarily on paraphrasing text. It has since expanded to include features for detecting AI-generated content, aiming to help users identify whether a piece of writing comes from a human or an AI model like ChatGPT. It’s used by students, writers, and professionals who need to analyze or refine their text.
Quillbot’s AI Detector
Features
AI Detection: Analyzes text to determine if it’s AI-generated, providing a percentage score to indicate the likelihood.
Sentence Highlighting: Points out specific parts of the text it flags as potentially AI-written.
Paraphrasing Tool: Rewrites text with options like Standard, Fluency, and Formal modes to adjust the style.
Multiple Languages: Supports detection and paraphrasing in various languages.
Ease of Use: Offers a straightforward interface where users can paste text and get results quickly.
Free Access: Available without a signup for basic detection, with limits on word count.
Pricing
Quillbot’s AI detector has a free version that lets you check up to 1,200 words per scan, with no signup required. For more features or higher limits, there’s a premium plan starting at $4.17 per month (billed annually), which includes unlimited paraphrasing and additional tools like grammar checking. Monthly billing is also available at a higher rate, around $9.95, depending on the plan.
3. ZeroGPT
ZeroGPT is a free online tool designed to detect whether text is generated by AI models, such as ChatGPT or Google Gemini, or written by a human. It’s used by a variety of people, including students, educators, writers, and professionals, to verify the authenticity of content. The tool uses its own DeepAnalyse™ technology, which is based on analyzing large datasets of both human and AI text to spot differences in patterns and style.
ZeroGPT’s AI Detector
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Features
AI Detection: Analyzes text and provides a percentage score indicating the likelihood of AI generation.
Sentence Highlighting: Identifies specific sentences or sections it flags as AI-generated.
Multilingual Support: Detects AI-generated text in multiple languages, making it useful for global users.
Long Text Scans: Handles up to 15,000 characters per scan in the free version, with higher limits in paid plans.
Batch File Uploads: Allows users to upload multiple files for analysis (available in paid plans).
Additional Tools: Includes features like paraphrasing, summarizing, grammar checking, and translation, though these are secondary to its detection focus.
API Access: Offers an API for organizations to integrate the detection technology into their own systems.
Pricing
ZeroGPT offers a free plan with no login required, allowing up to 15,000 characters per scan and basic detection features. For more frequent users, there’s a Pro plan at $7.99 per month (billed annually) or $9.99 per month (billed monthly), which includes up to 100,000 characters per scan, 50 batch file checks, and access to enhanced tools. The Max plan, at $18.99 per month (billed annually) or $26.99 per month (billed monthly), offers 150,000 character limit and increases batch file checks to 75 and includes more advanced features for heavy users or organizations.
4. Scribbr
Scribbr started as a proofreading and plagiarism-checking service aimed at students and academics, helping them polish their writing and ensure originality. Over time, it added an AI detector to its lineup, designed to identify text generated by AI models like ChatGPT, Copilot, or Gemini. The tool is used by students, educators, and professionals to check the authenticity of content, particularly in academic and publishing contexts.
Scribbr’s AI Detector
Features
AI Detection: Analyzes text to determine the likelihood of it being AI-generated, providing a percentage score.
Paragraph-Level Feedback: Offers detailed analysis by highlighting specific sections flagged as potentially AI-generated.
Multilingual Support: Detects AI content in languages including English, German, French, and Spanish.
Plagiarism Integration: The premium version pairs AI detection with plagiarism checks for a more complete content review.
Unlimited Checks: Allows users to run as many scans as needed, with word limits depending on the plan.
Privacy: Ensures user submissions remain private and are not stored or shared.
Pricing
Scribbr’s AI detector has a free version that lets you scan up to 1200 words per check, with no signup required. For higher character limit and more robust features, Scribbr directs you to use Quillbot instead.
5. GPTZero
GPTZero is an AI detection tool launched in 2022, designed to identify whether text is written by humans or generated by AI models, such as ChatGPT, Grok, or LLaMA. It was initially created with a focus on education, helping teachers and students verify the authenticity of academic work, but it’s also used by writers, editors, and businesses. The tool uses its own analysis methods to spot patterns in text and distinguish between human and machine writing.
GPTZero’s AI Detector
Features
AI Detection: Analyzes text and provides a probability score showing the likelihood of AI generation.
Sentence Highlighting: Identifies specific sentences or sections flagged as potentially AI-generated.
Deep Analysis: Offers a detailed breakdown of text metrics like perplexity and burstiness to explain its findings.
Batch File Uploads: Allows users to upload multiple files for analysis at once (available in paid plans).
Chrome Extension: Provides a browser extension for quick checks on web content.
API Access: Offers an API for organizations to integrate detection into their workflows.
Multilingual Support: Detects AI-generated text in multiple languages, including English, Spanish, and French.
Writing Feedback: Includes an optional feature to analyze writing quality alongside AI detection (available in premium plans).
Pricing
GPTZero offers a free plan with no signup required, allowing up to 5,000 characters per scan and 10,000 characters per month, limited to 3 scans per batch. For more features, the Essential plan is $14.99 per month, covering up to 150,000 words per month. The Premium plan, at $23.99 per month, increases the limit to 300,000 words per month. The Professional plan costs $45.99 per month with a limit of 500,000 words per month. Custom pricing is available for organizations needing API access or higher limits.
6. Turnitin
Turnitin is a widely used plagiarism detection service that has expanded to include AI detection capabilities, helping educators and institutions identify text that may have been generated by AI models like ChatGPT or paraphrased using AI tools. Launched in 1998, it primarily serves the education sector, with a focus on maintaining academic integrity by analyzing student submissions. The tool is integrated into many learning management systems, making it a common choice for schools and universities.
Features
AI Detection: Analyzes text to determine the likelihood of AI generation, providing a percentage score for AI-written content.
Paraphrasing Detection: Identifies text that may have been AI-generated and then modified using AI paraphrasing tools, with specific highlighting for such sections.
Plagiarism Checking: Scans submissions against a large database of academic papers, websites, and other sources to detect potential plagiarism, offering a similarity score.
Sentence Highlighting: Highlights specific sections of text flagged as AI-generated or AI-paraphrased.
Detailed Reports: Provides a breakdown of AI detection results alongside plagiarism analysis, accessible within the similarity report.
LMS Integration: Works seamlessly with learning management systems, allowing educators to review results within familiar workflows.
Multilingual Support: Detects AI-generated text in English, with plans to expand to other languages.
Pricing
Turnitin’s AI detection feature is not available as a standalone product; it’s bundled with its plagiarism and originality services. Pricing is institution-based, meaning schools, universities, or organizations purchase licenses for their staff and students. Costs vary depending on the size of the institution and the specific features licensed, but there is no free public access for individuals. Educators or students typically access the tool through their institution’s subscription, with no direct cost to them.
7. Copyleaks
Copyleaks is a content analysis platform that offers both plagiarism detection and AI detection services, designed to identify whether text is human-written or generated by AI models like ChatGPT, Gemini, or other language models. Launched in 2015, it serves a wide range of users, including educators, students, businesses, and content creators, with a focus on ensuring content originality and authenticity. The tool is available as a standalone platform and integrates with various learning management systems and APIs for broader use.
Copyleaks’ AI Detector
Features
AI Detection: Analyzes text to determine the likelihood of AI generation, providing a percentage score.
Sentence Highlighting: Identifies specific sentences or sections flagged as potentially AI-generated.
Plagiarism Detection: Scans text against a database of online content, academic papers, and internal documents to check for similarities.
Multilingual Support: Detects AI-generated and plagiarized content in over 100 languages, including English, Spanish, French, and German.
Cross-Platform Integration: Works with learning management systems like Canvas, Moodle, and Blackboard, as well as offering browser extensions and API access.
File Uploads: Allows users to upload multiple file types, such as PDFs, Word documents, and plain text, for analysis.
Detailed Reports: Provides a breakdown of AI detection and plagiarism results, including highlighted sections and source matches.
Team Management: Offers features for organizations to manage multiple users and track usage (available in business plans).
Pricing
Copyleaks offers different plans depending on whether you need the AI detector or plagiarism checker only or both AI detector and plagiarism checker. For individuals, pricing starts at $9.99 per month for up to 100 credits (25,000 words) of AI detection, with annual billing offering a discount. The AI detection and plagiarism checker bundle package costs $16.99 per month.
8. Sapling
Sapling is an AI-powered writing assistant launched in 2019, primarily focused on grammar, style, and autocomplete features for businesses and customer-facing teams. It has since added an AI detection tool to help identify whether text is generated by AI models, such as ChatGPT, Gemini, or other language models. The tool is used by customer support teams, sales professionals, writers, and educators to analyze and improve content authenticity and quality.
Sapling’s AI Detector
Features
AI Detection: Analyzes text to determine the likelihood of AI generation, providing a percentage score.
Sentence Highlighting: Identifies specific sentences or sections flagged as potentially AI-generated.
Grammar and Style Checks: Offers suggestions for improving grammar, style, and tone alongside AI detection.
Autocomplete: Provides real-time sentence completion suggestions to help users write faster (available in premium plans).
Multilingual Support: Detects AI-generated text and offers writing assistance in multiple languages, including English, Spanish, and French.
Integrations: Works with platforms like Gmail, Slack, Zendesk, and Salesforce, as well as offering a Chrome extension for broader use.
API Access: Provides an API for organizations to integrate AI detection and writing assistance into their systems.
Team Features: Includes tools for managing multiple users, tracking usage, and setting team preferences (available in business plans).
Pricing
Sapling’s AI detector is available for free with limited functionality, allowing up to 2,000 characters per scan without requiring a signup. For more features and higher limits, paid plans are available. The Pro plan starts at $25 per user per month and includes unlimited AI detection scans, grammar checks, and autocomplete features, with a minimum of one user. The Enterprise plan, designed for larger teams, offers custom pricing based on the number of users and specific needs, adding features like API access, advanced integrations, and team analytics.
9. SciSpace
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SciSpace is an AI-powered platform designed to assist with academic research, offering tools for literature reviews, AI detection, and writing assistance. Originally launched as Typeset, it has rebranded to focus on simplifying the research process for students, researchers, and educators. The tool integrates with a database of over 200 million research papers, aiming to help users understand, analyze, and create academic content.
SciSpace’s AI Detector
Features
AI Detection: Analyzes text to determine the likelihood of AI generation, providing a percentage score and detailed sentence-level reports.
Literature Review Assistant: Searches a database of over 200 million papers to answer research questions, presenting results in a table with filters like journal ranking and PDF availability.
AI Chat for PDFs: Allows users to upload PDFs and ask questions, receiving explanations or summaries of text, math, and tables.
Citation Generator: Automatically generates citations in various formats to streamline referencing.
Paraphraser: Rewords text with options for different tones and styles, supporting over 20 preset tones.
Data Extraction: Enables users to upload PDFs and extract specific data points, such as conclusions or methods, into a table for comparison.
Multilingual Support: Works with text in multiple languages, aiding in translation and analysis.
Chrome Extension: Provides quick access to features while browsing academic content online.
Video Abstracts: Allows users to create video summaries of their work for sharing on social media.
Pricing
SciSpace offers a free plan that includes basic features like limited AI detection, citation generation, and paraphrasing, with no signup required. For more advanced features, such as unlimited access to the literature review tool, enhanced data extraction, and API access, premium plans are available. Pricing starts at $20 per month for individuals, with custom pricing for teams, institutions, and enterprise users.
10. Grammarly
Grammarly is an AI-powered writing assistant launched in 2009, widely known for its grammar, spelling, and style checking features. It has since expanded to include an AI detection tool to identify whether text is generated by AI models, such as ChatGPT, Gemini, or other language models. The tool is used by students, professionals, writers, and businesses to improve writing quality and verify content authenticity.
Grammarly’s AI Detector
Features
AI Detection: Analyzes text to determine the likelihood of AI generation, providing a percentage score.
Sentence Highlighting: Identifies specific sentences or sections flagged as potentially AI-generated.
Grammar and Spelling Checks: Offers real-time suggestions to correct grammar, spelling, and punctuation errors.
Style and Tone Adjustments: Provides feedback on writing style, tone, and clarity, with options to adjust based on audience or intent.
Plagiarism Detection: Scans text against a database of web pages and academic papers to check for similarities (available in premium plans).
Multilingual Support: Detects AI-generated text and offers writing assistance in multiple languages, with a focus on English.
Integrations: Works with platforms like Microsoft Word, Google Docs, Gmail, and Slack, as well as offering a browser extension and desktop app.
Writing Goals: Allows users to set specific goals, such as formality level or domain, to tailor feedback.
Pricing
Grammarly’s Premium plan starts at $12 per month (billed annually) or $30 per month (billed monthly), including AI detection, plagiarism checks, and advanced style suggestions. The Business plan, designed for teams, starts at $15 per user per month (billed annually) with a minimum of three users, adding team management features. Custom pricing is available for larger organizations or educational institutions.
Are AI Detectors Reliable, and Should You Use Them?
AI detectors are handy tools for figuring out whether a piece of text is human-written or machine-generated, but they’re not perfect.
They can help spot patterns in writing, like overly smooth phrasing or robotic repetition, which is great for teachers checking homework, businesses ensuring authentic content, or writers double-checking their work.
But as AI gets smarter, some detectors struggle to keep up, especially with text that’s been edited or mixed with human input. That said, the tools I’ve covered here – like SurgeGraph, Quillbot, Scribbr, and others – offer a solid starting point for anyone needing to verify content.
Should you use them? It depends on your needs.
If you’re in a field where authenticity matters, like education or professional writing, they’re worth having in your toolkit. Just don’t rely on them blindly – always double-check results, especially for important decisions.
And if you’re worried about your AI-generated content getting flagged, tools like SurgeGraph offer a free AI humanizer, or you can use their Vertex AI writer to generate content that’s already human-like and skips detection hassles.
Frequently Asked Questions
What is the best AI detector?
The best AI detector depends on your specific needs, such as budget, text length, and use case. For example, SurgeGraph offers a free AI text detector with detailed analysis and an AI humanizer, making it a strong choice for content creators. Tools like Quillbot and Grammarly are popular for their ease of use, while Copyleaks and Turnitin cater to academic and business users with robust integrations. Compare features and pricing to find the one that suits you best.
How do AI detectors work?
AI detectors analyze text to identify patterns that suggest whether it’s human-written or AI-generated. They look at factors like sentence structure, word choice, and predictability, often using metrics like perplexity (how random the text is) and burstiness (variety in sentence length). Some tools also highlight specific sections they flag as AI-generated, helping users understand the results.
Are AI detectors accurate?
AI detectors can be reliable for clear-cut cases, but they’re not foolproof. Their accuracy varies depending on the tool, the AI model used to generate the text, and whether the content has been edited or mixed with human writing. It’s always a good idea to use results as a guide rather than a final judgment, especially for important decisions.
What is the best free AI detector?
Several tools offer free AI detection, making them great options if you’re on a budget. SurgeGraph provides a free AI detector with detailed sentence-by-sentence analysis, while Quillbot and ZeroGPT also offer free plans with limits on word count. Scribbr’s free version is another choice, though it caps scans at 500 words.
Can AI detectors spot ChatGPT content?
Yes, most AI detectors are designed to identify content generated by models like ChatGPT. Tools like Copyleaks, GPTZero, and Sapling analyze text patterns to flag content that matches ChatGPT’s style, though accuracy can vary, especially if the text has been heavily edited or paraphrased.
How can I bypass AI detection?
If your content is flagged as AI-generated, you can use tools to make it appear more human-like. For example, SurgeGraph offers a free AI humanizer to tweak flagged text, or you can use its Vertex AI writer to generate content that mimics your style and bypasses detection automatically.
What is the difference between AI detection and plagiarism detection?
AI detection identifies whether text was generated by an AI model, focusing on patterns like predictability and tone. Plagiarism detection, on the other hand, checks if text matches existing sources, such as web pages or academic papers.
Are AI detectors useful for SEO?
AI detectors can be helpful for SEO by ensuring your content feels authentic and human-like, which may improve user engagement and trust. While Google has said AI-generated content is acceptable if it’s high-quality, using a detector to verify or humanize your text can help you align with best practices and potentially rank better for competitive keywords.
Can AI detectors handle long documents?
Some AI detectors are better suited for long documents than others. SurgeGraph, for instance, can scan up to 50,000 characters, while ZeroGPT’s free plan handles up to 15,000 characters.
NOTE:
This article was written by an AI author persona in SurgeGraph Vertex and reviewed by a human editor. The author persona is trained to replicate any desired writing style and brand voice through the Author Synthesis feature.
Eli Taylor
Digital Marketer at SurgeGraph
Eli lives and breathes digital marketing and AI. He always seeks new ways to combine AI with marketing strategies for more effective and efficient campaign executions. When he’s not tinkering with AI tools, Eli spends his free time playing games on his computer.
