Noplag vs Plagiarism Checker X
Noplag
noplag.com
Plagiarism Checker X
plagiarismcheckerx.comSide by side
| Figure | Noplag | Plagiarism Checker X |
|---|---|---|
| Price from | $9.99/mo | Free |
| Free plan | Yes | Yes |
| Free trial | Yes | — |
| Open source | Yes | — |
| Web | Yes | — |
| Windows | Yes | Yes |
| macOS | Yes | — |
| Linux | Yes | — |
| API | Yes | — |
| Self-hosted | Yes | — |
| Plans published | 4 | 3 |
| Spec score · Plagiarism Checkers | 9.2 (#3) | 8.0 (#11) |
| Spec score · AI Plagiarism Checkers | 9.2 (#3) | 8.1 (#8) |
| AI detection | AI-content detection is marked as coming soon and is intended to appear as a separate signal. | The maker says its AI-generated content detector indicates whether content may have been produced by an AI tool or written by a human. |
| Founded | 2014 | 2012 |
| Headquarters | San Francisco, United States | 733 3rd Avenue, New York City, NY 10017, United States |
| Privacy | Noplag states that submitted documents are not used to train models or shared between accounts, and EU data residency is available. | The maker says documents remain on the user's computer during scanning and that customer content is not copied, stored, or sold. |
| Reports | Reports link each match to its source and show a similarity score and exact overlapping text, with PDF export. | Reports highlight matched similarity with colors and references and can be exported as Word or PDF documents. |
| Support | Free includes community Discord support, Pro includes email support, and Premium includes priority support with a 12-hour response target. | The pricing page lists 24/7 customer support with Professional and priority support with Business. |
Plans
Plagiarism Checker X
- BasicFree
- Professional$39.95, paid once
- Business$147.95, paid once
In their own words
Noplag
Noplag is an open-source plagiarism checker with a hosted cloud service and an engine released under Apache 2.0. Its current matching uses winnowing fingerprints and live-web comparison to find verbatim and near-verbatim copying; it does not detect paraphrase. Sources include the open web, Common Crawl, Wikipedia, academic indexes, the Noplag Database and users’ own folders. Submit DOCX, PDF, TXT, ODT or RTF files, paste text or provide a URL. Reports link matches to their sources, display similarity scores and exact overlapping text, and can be exported as PDFs. Detection is calibrated at launch for English, Spanish, Portuguese, Polish and Ukrainian. AI-content detection is marked as coming soon and intended as a separate signal. The free plan allows three checks per month, up to 2,500 words per check, with community Discord support. Pro costs $9.99 a month and includes 50 monthly checks, up to 25,000 words per check, database and academic-index matching, REST API and webhooks, and email support. A 14-day trial is listed.
Plagiarism Checker X
Plagiarism Checker X is Windows desktop software for checking documents and text against published web pages for plagiarism and similarity. Its online checker compares content with more than 16 billion pages. Bulk Comparison examines multiple documents in repositories, while Side-By-Side Difference places content in two windows to locate matching text. An AI detector indicates whether writing may have come from an AI tool or a human. A readability checker analyzes reading levels, extracts keywords and assesses difficulty. Reports mark matches with colors and references and can export to Word, PDF or Excel. The software accepts Word, PDF, text and other textual formats. Its interface is available in English, Spanish, French, German, Italian, Dutch and Portuguese, with content support for hundreds of languages. The maker says documents remain on the user’s computer and customer content is not copied, stored or sold. Basic is free with limited words and a daily search limit. Professional costs $39.95, paid once; Business costs $147.95, paid once.