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Check code for plagiarism,
instantly.

Professional code plagiarism detection for Python, Java, C++, JavaScript, and 65+ languages. Check against GitHub, Stack Overflow, and web sources.

A Codequiry report: LibrarySystem.java is 98% similar to code found online, with matches from GitHub Gist and Stack Overflow listed by score
Checks run inside your Codequiry account
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Enterprise Security
Instant Results
50+ Languages

GitHub Checking

Check millions of public repositories

Web Sources

Search across the entire internet

Stack Overflow

Detect code from Q&A sites

AI Detection

Identify AI-generated code

Enterprise Code Plagiarism Checker, a Modern MOSS Alternative

Codequiry is a modern MOSS alternative (Measure Of Software Similarity) for detecting copied code, source code plagiarism, and code similarity. Whether it's for an academic integrity review, a legal or copyright question, or a code audit, Codequiry finds code lifted from GitHub and Stack Overflow and returns detailed results in minutes.

Triple Layer Detection Technology

Unlike traditional plagiarism checkers that only compare submissions against each other, Codequiry uses Triple Layer Detection to provide the most comprehensive code plagiarism analysis available. Our advanced system checks across three critical dimensions simultaneously, catching plagiarism that other tools completely miss.

Layer 1: Peer-to-Peer Detection

Submission-to-Submission Comparison. Our algorithm compares every submission against every other submission in your batch. Detect collusion rings, shared solutions, and copied code between submissions with advanced token-based matching that catches even heavily modified copies.

  • Cross-submission analysis across the entire batch
  • Collusion ring detection (3+ submissions)
  • Historical submission comparison
  • Fuzzy matching for modified code

Layer 2: Web-Scale Scanning

Web-Wide Source Search. The game-changer that separates Codequiry from MOSS, JPlag, and Dolos. We search indexed web sources including GitHub repositories, Stack Overflow answers, Chegg solutions, Course Hero, coding forums, tutorial websites, Pastebin, and personal blogs.

  • 630M+ GitHub repositories
  • Stack Overflow & coding forums
  • Chegg, Course Hero, Quizlet
  • Tutorial sites & documentation

Layer 3: AI Code Detection

Detect AI-Generated Code. The newest and fastest-growing source of unattributed code. Our AI detection engine identifies code generated by ChatGPT, GitHub Copilot, Claude, Gemini, Grok, Cursor, Amazon CodeWhisperer, and other LLM-based code generators with Extremely High Accuracy.

  • ChatGPT & GPT-5.1 code detection
  • GitHub Copilot pattern recognition
  • Claude, Gemini, Grok detection
  • Style inconsistency analysis

AI Code Detection: Catch AI-Written Code

With the explosion of AI coding assistants like ChatGPT, GitHub Copilot, Claude, and Gemini, detecting AI-generated code has become critical for academic integrity, legal review and code audits. Codequiry's AI code detector uses advanced machine learning trained on millions of code samples to identify AI-written code with remarkable accuracy.

Multi-Layer Neural Networks

Trained on millions of code samples from GPT-5.1, Claude, Copilot, Grok, Gemini, and Cursor to reliably identify AI-generated patterns

Entropy & Pattern Analysis

Analyzes code entropy, comment patterns, error handling consistency, and stylistic uniformity that reveals AI authorship

Style Incongruence Detection

Flags when submitted code doesn't match an author's established coding patterns from earlier work

Obfuscation Detection

Detects attempts to disguise AI code through dead code insertion, variable renaming, and complex logic restructuring

Zeus™ Hyper Technology

At the heart of Codequiry's 95%+ accuracy is our proprietary Zeus™ Hyper technology. Unlike traditional tools that compare raw text, Zeus Hyper uses advanced AI-powered semantic analysis to understand what code actually does, not just what it looks like. This allows us to detect plagiarism even when someone renames variables, reorders functions, adds dead code, or uses sophisticated obfuscation techniques.

95%+ Detection Accuracy
427B+ Web Sources
65+ Languages
2-4 min Analysis Time

How to Check Code for Plagiarism

Using our enterprise code plagiarism checker is simple. Check code for plagiarism in just three easy steps:

1

Paste Your Source Code

Copy and paste the code you want to check for plagiarism into our online code editor. Our code plagiarism detector supports Python, Java, C++, C, C#, JavaScript, TypeScript, PHP, Ruby, Go, Rust, Swift, Kotlin, and 65+ programming languages.

2

Select Programming Language

Choose the programming language from the dropdown menu. Our plagiarism checker provides accurate code analysis with proper syntax highlighting for all major languages.

3

Get Comprehensive Results

Click "Check for Plagiarism" and our Triple Layer Detection checks the code against peers, web sources, and AI generation patterns. Get detailed similarity scores with source attribution.

Why Choose Codequiry Over MOSS?

Looking for a MOSS plagiarism checker alternative? While Stanford MOSS (Measure Of Software Similarity) was pioneering in 1994, it has significant limitations today. Here's why teams worldwide are switching to Codequiry:

Feature
Codequiry
MOSS
Web Scanning
✓ web sources
✗ None
AI Detection
✓ ChatGPT, Copilot, Claude
✗ None
Results Speed
✓ 2-4 minutes
✗ Hours/Days
Languages
✓ 65+ languages
~25 languages
Interface
✓ Modern web UI
✗ Command line
Anti-Obfuscation
✓ Zeus™ Hyper
✗ Basic

Code Plagiarism Detection for Academic Integrity, Legal Review and Audits

Our programming plagiarism checker is built for anyone who needs to know where code came from, whether that is an academic integrity review, a legal or copyright question, or a code audit. Reviewers can quickly detect code plagiarism, check source code similarity, and identify copied code from online sources. Our system checks against web sources, GitHub repositories, Stack Overflow answers, and uses AI detection to catch AI-generated submissions.

Triple Layer Detection

Peer comparison + Web scanning + AI detection in one comprehensive analysis

AI-Generated Code Detection

Catch ChatGPT, Copilot, Claude, and other AI-written code with Extremely High Accuracy

65+ Programming Languages

Python, Java, C++, JavaScript, TypeScript, Go, Rust, Swift, Kotlin, and more

In-House Detection Engines

Hexagram, built from scratch, and Zeus, optimized for speed

Anti-Obfuscation Technology

Catches variable renaming, code reordering, dead code insertion, and format changes

Side-by-Side Diff Reports

Visual comparison with highlighted matches and direct source links for evidence

Supported Programming Languages

Our code plagiarism checker supports 65+ programming languages and frameworks, more than many other tools including MOSS, JPlag, and Dolos. Check code for plagiarism in Python, Java, C++, JavaScript, and many more:

Python Java C++ C JavaScript TypeScript C# PHP Ruby Go Rust Swift Kotlin Scala SQL R MATLAB Julia Perl Haskell Lua Assembly Dart Groovy And 40+ more

Comprehensive Code Plagiarism Detection Features

  • Triple Layer Detection: Simultaneous peer-to-peer, web-scale, and AI code detection in one analysis
  • AI-Generated Code Detection: Identify ChatGPT, GitHub Copilot, Claude, Gemini, Grok, and AI-generated code
  • Web-Scale Scanning: Search web sources including GitHub, Stack Overflow, Chegg, and Course Hero
  • Zeus™ Hyper: Proprietary technology achieving 95%+ accuracy with semantic code understanding
  • Anti-Obfuscation Detection: Catches variable renaming, code reordering, dead code insertion, and format changes
  • AST/CFG Structural Analysis: Deep code structure comparison that understands algorithmic similarity
  • Collusion Ring Detection: Identify groups of 3+ submissions sharing code
  • Side-by-Side Diff Reports: Visual comparison with highlighted matches and source attribution
  • PDF Export: Generate detailed evidence reports for academic integrity boards and legal review
  • LMS Integration: Seamless integration with Canvas, Moodle, Blackboard, and other platforms
  • API Access: REST API for custom integrations and automated workflows
  • Batch Processing: Upload hundreds of submissions at once for large-scale analysis

What is Code Plagiarism and Why Check For It?

Code plagiarism occurs when someone copies source code from another programmer, website, repository, or AI tool without proper attribution. It can be an academic integrity violation, a copyright or licensing problem, or a risk hiding in a codebase. With the rise of AI coding assistants like ChatGPT and GitHub Copilot, detecting AI-generated code has become just as important as detecting copied code. Our code plagiarism detector with AI detection helps identify both copied and AI-written code by analyzing source code against billions of sources and AI generation patterns.

MOSS Alternative for Modern Code Plagiarism Detection

Stanford MOSS (Measure Of Software Similarity) was pioneering when introduced in 1994, but it wasn't built for today's challenges. MOSS compares submitted files; it does not independently search GitHub or Stack Overflow. MOSS cannot detect AI-generated code from ChatGPT or Copilot. MOSS requires command-line submission and email-based results. Codequiry is the premier MOSS alternative offering instant web-based plagiarism detection, real-time results, intuitive interface, web-scale scanning, AI code detection, and support for 65+ programming languages. Experience enterprise-grade plagiarism detection without the limitations of 1994 technology.

Academic Integrity, Legal and Code Audit Reviews

Looking to check code for plagiarism with confidence? Codequiry provides the comprehensive solution with Triple Layer Detection. Before you make a call on a submission or a codebase, use our plagiarism detector to check for shared code, web source copying, and AI-generated code. Detect code from Chegg, Course Hero, GitHub, Stack Overflow, and AI tools, with detailed, evidence-based reports.

For Reviewers: Detect Code Plagiarism in Any Submission

Reviewers can use our code plagiarism checker to quickly verify submissions across all three detection layers. Detect copied code from GitHub, Stack Overflow, Chegg, previous submissions, and AI assistants. Our plagiarism detector makes it easy to check code of any size for plagiarism, with comprehensive detection trusted by institutions and businesses worldwide.

Ready for Enterprise-Grade Code Plagiarism Detection?

Get detailed plagiarism reports, batch code checking, team collaboration tools, API access, and advanced features. Experience unlimited code plagiarism detection with our industry-leading platform.