npm

cpd — Copy/Paste Detector

Fast copy/paste detector for programming source code. Rust rewrite of jscpd, supports 224 language formats.

jscpd v5 is the Rust engine — a self-contained binary. The TypeScript engine (v4) is maintained on the master-v4 branch and published as jscpd@4.

Packages

Package	Installs	When to use
jscpd	jscpd	Default install; the jscpd command
cpd	cpd	Shorter command name only
basta	basta	Dead code, not duplication — a separate binary

jscpd and cpd install the identical Rust binary. For both jscpd and cpd command names from a single install, use crates.io: cargo install jscpd.

Install

# npm — installs the jscpd command
npm install -g jscpd

# npm — installs only the cpd command
npm install -g cpd

# crates.io — installs both jscpd and cpd binaries
cargo install jscpd

# dead code detection — a separate binary and a separate npm package
npm install -g basta
cargo install basta

# Nix — run without installing
nix run github:kucherenko/jscpd -- /path/to/code

# Nix — install permanently
nix profile install github:kucherenko/jscpd

# Homebrew (macOS/Linux)
brew install jscpd

Prebuilt binaries for 8 platforms (macOS arm64/x64, Linux arm64/x64 with glibc or musl, Windows arm64/x64) — no Node.js runtime required.

Quick Start

# Scan current directory
cpd .

# Scan specific paths
cpd ./src ./lib

# Minimum tokens/lines for a clone
cpd . --min-tokens 30 --min-lines 3

# Git blame with side-by-side author comparison
cpd . --blame --reporters console-full

# Output to JSON + HTML
cpd . --reporters json,html

# Fail CI if duplication exceeds threshold
cpd . --threshold 10

# List all supported formats
cpd --list

Options

Flag	Short	Default	Description
--min-tokens	-k	50	Minimum tokens to consider a duplicate
--min-lines	-l	5	Minimum lines to consider a duplicate
--max-lines	-x	—	Maximum lines per duplicate block
--mode	-m	mild	Detection mode: mild, weak, strict
--skip-comments	—	—	Alias for --mode weak
--format	-f	all	Comma-separated formats to check
--ignore-pattern	-i	—	Glob patterns to ignore
--reporters	-r	console	Comma-separated reporters
--output	-o	report	Output directory for file reporters
--config	-c	—	Path to config file (.jscpd.json)
--threshold	-t	—	Max duplication % before exit 1
--blame	-b	—	Enrich clones with git blame data
--skip-local	—	—	Skip clones within the same directory
--skip-isolated	—	—	Skip clones between isolated monorepo folders (e.g. packages/a|packages/b)
--silent	-s	—	Suppress console output
--list	—	—	List all supported formats and exit

For the full options list, see docs/rust.md.

Reporters

Reporter	Output
console	Clone list + statistics table (default)
console-full	Source snippets + blame comparison
json	report/jscpd-report.json
html	report/jscpd-report.html
sarif	report/jscpd-report.sarif (GitHub Code Scanning)
ai	Token-efficient output for LLM pipelines
badge	report/jscpd-badge.svg + report/jscpd-lines-badge.svg

Plus: xml, csv, markdown, xcode, threshold, silent.

Config File

Create .jscpd.json in your project root:

{
  "minTokens": 30,
  "minLines": 3,
  "format": ["javascript", "typescript", "python"],
  "ignorePattern": ["node_modules", "dist", "*.min.js"],
  "reporters": ["console", "json"],
  "output": "report",
  "threshold": 5,
  "blame": false
}

Cross-Format Detection

Vue SFC (.vue), Svelte (.svelte), Astro (.astro), and Markdown files are tokenized per-block, enabling duplicate detection across file types.

Programmatic Usage (Rust)

use cpd_finder::orchestrate::{RunConfig, run};

let config = RunConfig {
    paths: vec!["./src".into()],
    min_tokens: 50,
    ..Default::default()
};

let result = run(&config).unwrap();
println!("Found {} clones", result.clones.len());
println!("Analyzed {} files", result.statistics.total.sources);

Architecture

cpd (CLI binary)
 ├── cpd-core      — Detection algorithm (Rabin-Karp rolling hash)
 ├── cpd-tokenizer — Language tokenization (224 formats)
 ├── cpd-finder    — File walking, orchestration, git blame
 └── cpd-reporter  — Output formatting (15 reporters)

See docs/rust.md for detailed documentation and the v4 migration table, and docs/api.md for the Rust API.

License

MIT