JPlag vs Quetext AI Detector

JPlag is free, open-source software for finding pairwise similarities among submitted programs. It examines program syntax and structure to help detect source-code plagiarism and collusion, especially in student programming exercises, and can also identify duplicated or stolen software parts. It does not compare submissions with the internet. Supported inputs include Java, C, C++, C#, Python, JavaScript, TypeScript, Go, Kotlin, R, Rust, Swift, Scala, LLVM IR, Scheme, EMF, SCXML, text, and multi-language projects. JPlag runs locally, with the project stating that source code and plagiarism results are not sent externally. You can use its command-line interface, Java API, or Maven Central dependency. A bundled report viewer opens generated or existing reports. Base-code directories can exclude shared starter code, while matching-token sensitivity is adjustable. The default report lists up to 2500 comparison pairs, configurable with -n. Running or building it requires Java SE 25.

Quetext AI Detector analyzes writing for signs of AI-generated text, including text associated with ChatGPT, GPT-5, Claude, Gemini, and Llama. It examines writing patterns, perplexity, and burstiness, then presents line-by-line results with a confidence score. The same scan checks for plagiarism. Quetext cautions that short phrases can be difficult to assess and that longer, structured text works better.

The free plan includes AI detection and plagiarism checks for up to 1,000 words, plus Summarizer and Humanizer limits of 2,000 words. AI Detector Only costs $7.99 a month, billed annually, and includes 50,000 words per month, reports, and API access. The Chrome extension checks webpages, Google Docs, WordPress, and plain HTML. The API accepts text or files and returns plagiarism and AI scores, with integrations described for Canvas, Blackboard, and custom portals. Reports can be downloaded or shared as PDFs. Quetext’s privacy policy says submitted content and usage data may be used for AI training and quality processes by default; it offers an opt-out for future inclusion of identifiable personal data.