Three scans. One platform.
Unlimited MOSS.
All-in-one source code plagiarism detection — peer copying, web copying, and AI-generated code. Group similarity, web plagiarism, and AI detection in a single check with native multi-threading.
The Power of Three
Every check runs three distinct scans simultaneously — detecting peer copying, web plagiarism, and AI-generated code in a single operation.
MOSS Group Similarity
Compare all student submissions against each other to detect peer-to-peer code copying with precision matching.
- All-pairs comparison
- Variable/structure renaming detection
- Winnowing fingerprint algorithm
- Similarity percentage per pair
Web Plagiarism for Code
Scan every submission against 1 trillion+ online sources — GitHub, Stack Overflow, code repositories, tutorials, and more.
- 1T+ indexed code sources
- GitHub & Stack Overflow matching
- Real-time web crawling
- Source URL attribution
AI Detection for Code
Identify AI-generated code from ChatGPT, Claude, Copilot, and other AI assistants with a Stanford-developed algorithm.
- 90%+ detection accuracy
- GPT-4, Claude, Copilot detection
- Line-level AI probability
- Multi-model coverage
Languages Supported
Python, Java, C/C++, JavaScript, Go, Rust, Ruby, PHP, Swift, Kotlin, and 55+ more.
Unlimited Usage
No per-check fees. Unlimited group similarity, unlimited assignments, unlimited submissions.
Native Multi-Threading
Process all submissions in parallel with native threading. Up to 50x faster than Stanford MOSS.
How It Works
Four simple steps from upload to results. Multi-threaded processing handles everything in parallel.
Upload Submissions
Upload student code files as a ZIP or individually. Supports 80+ submissions per check.
Select Scans
Choose group similarity, web plagiarism, AI detection — or run all three simultaneously.
Multi-Threaded Processing
Native multi-threading processes every submission in parallel for maximum speed.
Review Results
View detailed reports with similarity scores, matched sources, line-by-line comparisons, and AI probability.
Built for Speed
Native multi-threading and local processing deliver results faster than any remote MOSS service.
Process 80+ submissions in under 2 minutes
- Native multi-threading — every submission processed in parallel threads, not sequentially
- 50x faster than Stanford MOSS — no waiting for remote servers or queues
- Native performance — optimized engine runs on Codequiry's infrastructure
- Under 2 minutes for a full 3-scan check with 80+ submissions
- Own MOSS server — no dependency on Stanford's infrastructure
How MOSS Commercial Compares
See how MOSS Commercial stacks up against Stanford MOSS and free MOSS online tools.
| Capability | MOSS Commercial | Stanford MOSS | Free MOSS Online |
|---|---|---|---|
| Group Similarity | Yes | Yes | Limited |
| Web Plagiarism Scan | 1T+ sources | No | No |
| AI Detection for Code | 90%+ accuracy | No | No |
| Simultaneous Submissions | 80+ | 100 files max | Varies |
| Multi-Threading | Native | Sequential | No |
| Unlimited Usage | Unlimited | Rate limited | No |
| Languages | 65+ | ~25 | ~10-15 |
| Results Format | Web UI + API + JSON | HTML only | HTML only |
| Support | Priority | None | Basic |
| Setup Required | None — instant | Perl + email registration | Varies |
Who It's For
MOSS Commercial serves educators and institutions who need reliable, scalable code plagiarism detection.
CS Departments
Run MOSS across all programming courses with unlimited checks, 65+ languages, and three-in-one scanning.
Teaching Assistants
Grade faster with instant plagiarism reports. Upload submissions, run checks, and review results in minutes.
Programming Contests
Verify submission originality in competitive programming events with fast, accurate similarity detection.
Bootcamps & MOOCs
Scale code integrity checks across hundreds of online students with unlimited usage and API access.
Academic Integrity Offices
Investigate suspected plagiarism cases with detailed similarity reports, source attribution, and AI detection.
Research Labs
Ensure research code originality and detect unauthorized code reuse across research group submissions.
One Purchase. Unlimited MOSS.
Pick the plan that fits your needs. MOSS Commercial is included in every plan.
For individuals and teams getting started with code integrity.
- Checks & Detection
- 120 scans · ∞ submissions
- Unlimited Group Similarity
- AI-Written Code Detection
- Scan GitHub, StackOverflow, Chegg & 1T+ sources
- Engines
- Hexagram™ v2.0.1 Fast
- Dolos + JPlag included
- 65+ programming languages
- Platform
- Web Dashboard + Desktop Client
- API/CLI access
- Customer support
Better detection engines, more scanning power, more web sources.
- Checks & Detection
- 460 scans · ∞ submissions
- Unlimited Group Similarity
- AI-Written Code Detection
- Scan GitHub, StackOverflow, Chegg & 1T+ sources
- Engines
- Hexagram™ v2.0.1 Fast
- MOSS Limited
- Dolos + JPlag included
- Custom engine builder
- 65+ programming languages
- Scale & Limits
- Unlimited student seats & submissions
- Unlimited assignments
- No upload limits
- Platform
- Web Dashboard + Desktop Client
- Unlimited API/CLI access
- LMS integrations
- 3 admin seats
- Priority support
Unlock everything in Codequiry forever. All new features & updates included. Rapid built-in.
- Premium Engines Unlocked
- Zeus™ Detection Suite
- MOSS Enterprise
- MOSS Commercial
- MOSS Commercial version included
- MOSS Server access via client interface
- Rapid Included
- Unlimited web, AI & similarity scans
- Unlimited results & file storage
- Dedicated server (16 cores)
- No subscription needed
- Forever Benefits
- Stanford MOSS algorithm integration
- Cross-semester detection
- All future features & updates
- Priority feature requests
Optional add-on for Grow & Advanced. Unlimited scanning, storage, and processing.
- Unlimited Scanning
- Unlimited web, AI & similarity scans
- Storage & Scale
- Unlimited results & file storage
- Unlimited processing scale
- Performance
- Priority queuing
- Dedicated server (16 cores)
- Dedicated support staff
- Privacy & Terms
- Never used for matching
- Cancel anytime
Frequently Asked Questions
MOSS Commercial is Codequiry's enhanced version of the Stanford MOSS plagiarism detection system. It includes three scans in one — group similarity (MOSS), web plagiarism detection, and AI-generated code detection — all with unlimited usage, native multi-threading, and support for 65+ programming languages.
Stanford MOSS only provides group similarity checking with a 100-file limit. MOSS Commercial adds web plagiarism scanning across 1 trillion+ sources, AI-generated code detection, supports 80+ simultaneous submissions, includes native multi-threading for 50x faster results, and provides unlimited usage with no quotas.
The three scans are: (1) MOSS Group Similarity — compares all submissions against each other to detect peer-to-peer copying, (2) Web Plagiarism for Code — scans against 1 trillion+ online sources including GitHub and Stack Overflow, (3) AI Detection for Code — identifies AI-generated code from GPT, Claude, Copilot, and other AI models.
MOSS Commercial supports 80+ simultaneous submissions per check. With native multi-threading, all submissions are processed in parallel for maximum speed — most checks complete in under 2 minutes.
Yes. The Advanced plan includes unlimited group similarity checks, unlimited assignments, and unlimited submissions. Web and AI scans use included credits, with the option to add the Rapid add-on for fully unlimited scanning across all three types.
MOSS Commercial supports 65+ programming languages including Python, Java, C, C++, JavaScript, TypeScript, Go, Rust, Ruby, PHP, Swift, Kotlin, R, MATLAB, SQL, HTML/CSS, and many more.
MOSS Commercial is up to 50x faster thanks to native multi-threading and local processing. Most checks with 80+ submissions complete in under 2 minutes, compared to 10-30+ minutes with Stanford MOSS.
The AI detection uses a Stanford-developed algorithm with 90%+ accuracy to detect code generated by GPT-4, ChatGPT, Claude, GitHub Copilot, Gemini, and other AI coding assistants.
Yes. MOSS Commercial includes Codequiry's own MOSS server infrastructure, so you don't need to register for or depend on Stanford's MOSS server. This provides better reliability, speed, and no external dependencies.
MOSS Commercial is included in the Codequiry Advanced plan. Visit the pricing page, select the Advanced plan, and you'll have immediate access to all three scans, unlimited MOSS, and the full Codequiry platform.
Stop guessing. Start detecting.
Three scans in one check. Unlimited MOSS. Native multi-threading. The most complete code plagiarism detection available.