jscpd

What it is

Copy/paste detector for programming source code. Supports 224+ formats. AI-ready with MCP server and token-efficient reporter. Now with a Rust-powered engine — 24-37x faster.

How it works

Implements Rabin-Karp style detection to find duplicated code blocks across files. Provides multiple engines (TypeScript v4 and Rust v5) with reporters and optional AI-ready reporting.

Getting started

# Install (all platforms — installs the jscpd command)
curl -fsSL https://jscpd.dev/install.sh | bash

Quick configuration / usage notes

• TypeScript engine (Node.js, v4):
  • npm install -g jscpd@4
  • jscpd /path/to/code
  • or npx jscpd@4 /path/to/code
• Rust engine (v5):
  • npm install -g jscpd@5
  • jscpd /path/to/code
• Rust engine — cpd command only:
  • npm install -g cpd
  • cpd /path/to/code
• Rust-native install (exposes both jscpd and cpd):
  • cargo install jscpd
• Nix:
  • nix run github:kucherenko/jscpd -- /path/to/code
  • or permanently: nix profile install github:kucherenko/jscpd
• Homebrew:
  • brew install jscpd

Recent releases

• v5.0.14 (2026-07-27): New feature --cross-formats to detect across related formats via format equivalence groups.
• v5.0.12 (2026-07-08): Rename cpd binary and npm packages to jscpd to avoid collisions.
• v5.0.10 (2026-06-17): cpd (Rust) v5.0.10
• v5.0.9 (2026-06-13): GitHub Action for jscpd (Rust v5)
• v5.0.8 (2026-06-12): Bug fixes related to mmap and large repositories.

Traction

• Stars: 5966

Behind the repo

• Maintainer/organization: kucherenko
• License: MIT
• Last push: 2026-08-04

Caveats

• License: MIT
• Age: created 2013-05-29
• Open issues: 51