18.3
Noplag is an open-source plagiarism checker, with a hosted cloud service and an engine released under Apache 2.0.
Free planOpen sourceWebAPILinux
Best Plagiarism Detection Software in 2026
Reviewing text for possible plagiarism calls for a tool that fits both the material and the way you work. Compare Noplag, Noplag Engine, and Plagium on maximum check size and supported languages, especially when your documents vary in length or language. AI detection and API access are additional capabilities to consider. Browser extensions and LMS integrations may be relevant depending on where checks fit into your…
28.0
Plagiarisma is an originality checker that scans text against web sources, books, and academic papers.
Free planAndroidWebAPI
38.0
Plagium analyzes textual similarity and looks for writing patterns compatible with AI-generated content.
Free planAndroidiOSWeb
- 4
Dolos
Dolos is a free, open-source tool for finding similarities between source-code submissions, particularly for teachers reviewing programming tests,…
Free planOpen sourceWebAPILinuxmacOS7.7Free plan - 5
Originality.ai
Originality.ai offers tools for checking AI-generated text, plagiarism, facts, readability, grammar, spelling, and content quality.
Free planWebAPIExtension7.6From $12.95 a month - 6
Copyscape
Copyscape checks web content and newly created human- or AI-generated text for plagiarism and duplicate material found online.
Free planWebAPISelf-hosted7.5From $4.95 a month - 7
GPTZero
GPTZero identifies likely AI-generated writing and highlights potential AI use at document, sentence, and word level.
Free planWebAPIExtension7.5From $8.33 a month - 8
JPlag
JPlag compares programs with one another to identify pairwise similarities that may indicate source-code plagiarism or collusion.
Free planOpen sourceWebAPILinuxmacOS7.5Free plan - 9
Winston AI
Winston AI detects AI-generated text and images and includes plagiarism checking and other content-integrity tools.
Free planWebAPIExtensionSelf-hosted7.5From $189 a month - 10
Copyleaks AI Detector
Copyleaks AI Detector identifies AI-written text, including text blended with human writing.
WebAPIExtensionSelf-hosted7.2 - 11
Noplag Engine
Noplag Engine is an open-source tool for finding verbatim and near-verbatim matches against a corpus you control.
Free planWebAPILinuxmacOS7.1From $9.99 a month - 12
SmallSEOTools Plagiarism Checker
SmallSEOTools Plagiarism Checker compares submitted writing with online material and returns a report showing where matches appear.
Free planWebAPIExtension6.9From $94.08 a year - 13
DrillBit
DrillBit is an AI-powered platform for plagiarism detection and content integrity.
AndroidiOSWebAPI6.8$5 one-time - 14
Pangram
Pangram checks text and images for AI-generated content and also offers plagiarism detection.
Free planWebAPIExtension6.8From $20 a month - 15
Plagius
Plagius analyzes academic papers and other documents for possible plagiarism by checking the internet or local files.
WebmacOSWindows6.8From $58.80 a year - 16
Quetext AI Detector
Quetext AI Detector analyzes writing for signs of AI-generated text and displays line-by-line results with a confidence score.
Free planWebAPIExtension6.8From $7.99 a month - 17
Codequiry
Codequiry checks submitted source code for plagiarism and AI-generated code, helping educators verify student work.
WebAPILinuxmacOS6.7From €25.76 a month - 18
PlagiarismCheck.org
PlagiarismCheck.org checks text originality, verifies authorship, detects AI-generated content, and provides writing checks.
WebAPIExtension6.2$5.99 one-time - 19
DupliChecker
DupliChecker is an online collection of SEO and text analysis tools, including a plagiarism checker that assesses the originality of text.
WebAPI6.1From $9.99 a month - 20
iThenticate
WebAPI6.1$125 one-time - 21
MOSS
MOSS measures program similarity and has primarily been used to identify possible plagiarism in programming classes.
Free planWebLinux6.1Free plan - 22
PlagPointer
PlagPointer is a web service that checks documents for plagiarism and AI content in one scan.
Web6.1 - 23
Scribbr Plagiarism Checker
Scribbr Plagiarism Checker is a web service for comparing academic work with online and published sources.
Web6.1$19.95 one-time - 24
PlagiarismDetector.net
PlagiarismDetector.net is an online service for checking plagiarism and similarity in text.
WebAPIExtension6.0From $9.99 a month - 25
Plag.ai
Plag.ai is a web service for plagiarism checking, AI-text detection, and translated-plagiarism analysis.
Web5.9From €14.95 a month