CodeMatch vs QuickDup

CodeMatch is a Windows program from SAFE Corporation for comparing source-code files across two directories, including their subdirectories. It ranks file pairs by correlation scores from 0 to 100, helping an examiner reduce many combinations to a smaller review list. Its hybrid methods compare statements, comments and strings, instruction sequences, and identifiers. Reports can show the material behind high correlations in detailed HTML, while a database export can produce an HTML summary. SAFE lists languages including C, C++, C#, Java, JavaScript, Python, SQL, Swift, Verilog, and VHDL, and says requested languages can usually be added within days. The maker also describes uses such as finding open-source code in proprietary software, assessing common authorship, and identifying shared algorithms. A press release allows no-charge comparison of up to 1 megabyte of source code. CodeMatch assists expert review rather than precisely identifying plagiarism. It is paid, with a free plan and trial, but no CodeMatch price is listed.

QuickDup is a repository code clone detector that finds candidate duplicate patterns using changes in indentation and the first word on each line. It skips comments and blank lines, tokenizes source lines and uses Jaccard similarity to filter patterns below a default 75% threshold. It does not parse abstract syntax trees. Detection options include normalized-indent, word-indent, word-only and inlineable strategies. The README lists comment-prefix detection for languages including Go, C and C++, Java, JavaScript and TypeScript, C#, Python, Ruby, SQL, Lua and MATLAB. QuickDup can emit GitHub Actions annotations for inline pull request comments and restrict them to files changed against a Git reference. Results are written as machine-readable JSON in a .quickdup directory. Incremental caching is available only for the word-indent strategy; other listed strategies re-parse files on each run. The README reports processing about 100,000 lines in about 500 ms on 8 cores. QuickDup is free under the MIT License, with installers for Linux, macOS and Windows, or installation from source with Go.