Copyscape vs Plagium
Copyscape
copyscape.comPlagium
plagium.comSide by side
| Figure | Copyscape | Plagium |
|---|---|---|
| Price from | $4.95/mo | $19.98/mo |
| Free plan | Yes | Yes |
| Free trial | Yes | — |
| Open source | — | — |
| Web | Yes | Yes |
| iOS | — | Yes |
| Android | — | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 5 | 9 |
| Spec score · Plagiarism Detection Software | 9.2 (#2) | 8.9 (#8) |
| Spec score · AI Plagiarism Checkers | 9.2 (#2) | 9.0 (#5) |
| API | The Premium API supports automated URL, text, AI-detector and private-index operations with JSON, XML or HTML responses. | The institutional tier includes API access, and Plagium publishes API v3 and API v2 documentation. |
| Founded | Crunchbase lists the company as founded in 2003. | 2006 |
| Headquarters | Crunchbase lists Copyscape in Tel Aviv, Israel. | New York, USA and France |
| Praise: ease and accuracy | Independent reviewers repeatedly praise Copyscape as simple to use, quick, accurate for duplicate-content checks and useful for validating writers’ web content. | The sole Capterra reviewer praised ease of use, broad source comparison and detection accuracy, reporting no negative experience. |
| Rating on Capterra | 4.8 out of 5 from 71 reviews | 5.0 out of 5 from 1 review. |
| Rating on GetApp | 4.8 out of 5 from 71 reviews | 5.0 out of 5 from 1 review. |
| Rating on Trustpilot | 2.4 out of 5 from 6 reviews | 3.3 out of 5 from 2 reviews. |
| Support | Copyscape accepts questions, comments, and suggestions through its contact form. | Published support channels include a help center, email or help-desk support, FAQs/forum and priority email on paid tiers. |
| What it does | Copyscape searches online content for matching or copied text and supports originality checking for human- and AI-generated material. | Plagium compares submitted writing with online material to identify possible plagiarism and separately estimates whether text appears machine generated. |
Plans
Copyscape
- Free CopyscapeFree
- Copyscape Premium$0.03, paid once
- Copysentry Weekly protection$4.95 a month
- Copysentry Premium daily protection$19.95 a month
- Copyscape EnterprisePriced on request
Plagium
- FreeFree
- Free accountFree
- Single document$2, paid once
- Credit packages$7.95, paid once
- Unlimited$19.98 a month
- Institutional$1,200 a year
- InstitutionsPriced on request
- Monthly planPrice not published
- Prepaid planPrice not published
In their own words
Copyscape
Copyscape checks web pages and newly written human- or AI-generated content for plagiarism and duplicate text found online. Its free checker scans a URL and presents a word-by-word comparison of results, but shows no more than 10 search results and limits scans per website. Premium accepts pasted text as well as PDF and Word uploads for originality checks. Its Batch Search can process up to 10,000 pages in one operation, with each page billed like a regular search. The Premium API can automate plagiarism and AI checks and return results in JSON, XML, or HTML; a WordPress plugin supports checks in a WordPress workflow. Premium users can create a private index of their own content, accessible only through their Copyscape account. Copysentry monitors selected pages daily or weekly and emails alerts when it finds copies. Enterprise can be hosted on-premises or in a private cloud. Copyscape says it uses Google for search and then processes results with proprietary algorithms. It warns that AI detector results may misclassify human or AI text and should not be the sole basis for disciplinary action.
Plagium
Plagium analyzes text for similarity with other material and offers a separate tool for identifying patterns compatible with AI-generated writing. Its plagiarism service compares submitted text with an online database and reports similarities with links to original sources. The AI Detector uses statistical and probabilistic analysis of writing patterns. Deep Search accepts Microsoft Word, PDF, and native text files; Google Drive integration and a Google Docs add-on support document analysis. Institutional users can access an API, while business solutions can integrate with corporate CRM, ERP, and document-management systems. Plagium presents solutions for educational institutions, publishers, editors, companies, researchers, and compliance teams. The free account costs nothing and allows five daily searches with a 4,000-character limit, but excludes Deep Search and API access. Plagium says submitted content remains owned by the user and is processed for analysis, report generation, and service improvement. Reports are automated estimates rather than definitive proof, and private, unpublished, or non-indexed material may not be detected.