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Best Plagiarism Detection Software in 2026
Plagiarism detection software helps you review writing for material that may have appeared elsewhere. Compare maximum check size and supported languages with the documents you expect to review, and consider whether LMS integrations or a browser extension fit your workflow. AI detection and API access are additional listed capabilities; free-plan availability and paid-from pricing help frame access and cost. Noplag, Noplag Engine, and JPlag are among the entries to compare against your review process.
- 28 apps
- Research read 23 Sept 2026
- How the order is worked out
- 1
Dolos
Free plan Open source APILinuxMac+3Dolos focuses on similarities between source code submissions, with reports that show overlap at the file-pair level.
- 2
JPlag
Free plan Open source APILinuxMac+3JPlag provides local, pairwise code comparison through a CLI or Java API, with support for many languages and formats.
- 3
Noplag
Free plan Open source APILinuxMac+3Noplag provides source-linked matching reports for verbatim and near-verbatim copying, with multiple submission formats and a free tier.
- 4
Copyleaks AI Detector
Free plan APIExtensionSelf-hosted+1Copyleaks combines multilingual AI-text detection with explanations, integrations, and an API.
7.6 Visit site - 5
Copyscape
Free plan APISelf-hostedWebCopyscape offers URL checks as well as paid options for document checks, batch searches, and monitoring. Treat AI detector results as one input rather than a sole basis for disciplinary decisions.
- 6
GPTZero
Free plan APIExtensionWebGPTZero combines AI-writing detection with writing and classroom tools, and offers web, extension, and API access.
- 7
Noplag Engine
Free plan APILinuxMac+3Noplag Engine focuses on matching copied or near-copied passages in a controlled corpus, with a local deployment option and a hosted service that adds live-web search.
- 8
DupliChecker
Free plan APIWebChoose DupliChecker if you want online plagiarism checking alongside SEO tools, or a free AI detector that accepts pasted text and file uploads.
- 9
Originality.ai
Free plan APIExtensionWebOriginality.ai combines AI detection with plagiarism, fact, readability, and writing checks across web, extension, and API options.
- 10
Plagiarisma
Free plan AndroidAPIExtension+2Plagiarisma combines text originality checks with tools for paraphrasing and AI detection across its web, Windows, and Docs offerings.
- 11
MOSS
Free plan LinuxWebMOSS can surface similar passages across programming submissions, but it does not determine whether plagiarism occurred.
- 12
Pangram
Free plan APIExtensionWebPangram combines AI-content checks, plagiarism detection, document uploads, and feed scanning in web, extension, and API offerings.
- 13
Plagium
Free plan AndroidAPIExtension+2Plagium combines text similarity checking with a separate AI Detector and supports several document workflows.
- 14
PlagiarismCheck.org
Free plan APIExtensionWebChoose PlagiarismCheck.org if you need originality, authorship or AI-content checks with browser access and PDF reports.
- 15
PlagiarismDetector.net
Free plan APIExtensionWebChoose PlagiarismDetector.net if you need web-based plagiarism checks with unlimited quick searches, document uploads, reports, or integration options.
- 16
Quetext AI Detector
Free plan APIExtensionWebQuetext combines AI detection with plagiarism checks and offers browser, API, and report workflows.
- 17
Winston AI
Free plan APIExtensionSelf-hosted+1Winston AI combines text and image detection with plagiarism checking, OCR and shareable reporting.
- 18
Plag.ai
Free plan WebChoose Plag.ai if you need web-based plagiarism, AI-detection, or translated-plagiarism checks, especially across languages.
- 19
SmallSEOTools Plagiarism Checker
Free plan APIExtensionWebSmallSEOTools Plagiarism Checker offers multiple input methods, match details, and report exports, with a free scan cap of 1,000 words.
- 20
Codequiry
Free trial APILinuxMac+2Codequiry combines source comparison, AI detection, language coverage, and review tools for academic or engineering workflows.
- 21
Scribbr Plagiarism Checker
Free plan WebScribbr offers a free initial report and detailed paid reports for academic checks, with support for multiple languages and file formats.
- 22
WINNOWR
Free plan APILinuxSelf-hosted+1Choose WINNOWR if an institution wants free, API-based web-source matching with reviewable reports and the option to self-host.
- 23
Codeleaks
Paid APISelf-hostedWebCodeleaks focuses on identifying code origins, reuse, and licensing needs across repositories and workflows. Teams should review custom pricing and scan-credit usage before proceeding.
- 24
DrillBit
Paid AndroidAPIiPhone+1DrillBit combines source matching with AI-content detection and several integration routes, serving both individual and organizational use.
- 25
Plagius
Free trial MacWebWindowsPlagius combines document similarity checks with an AI-generation estimate and detailed reports.
#1Places #1, #2, #3, #4, #5 on this list can be bought by the makers of the software on it. See the price
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