kucherenko/jscpd

---

kucherenko/jscpd.json

{
  "createdAt": "2013-05-29T06:19:20Z",
  "defaultBranch": "master",
  "description": "Copy/paste detector for programming source code.",
  "fullName": "kucherenko/jscpd",
  "homepage": "",
  "language": "TypeScript",
  "name": "jscpd",
  "pushedAt": "2025-11-22T17:31:27Z",
  "stargazersCount": 5093,
  "topics": [
    "clones-detection",
    "code-quality",
    "copy-paste",
    "cpd",
    "detect-duplications",
    "detector",
    "duplicates",
    "duplications",
    "quality"
  ],
  "updatedAt": "2025-11-26T00:06:58Z",
  "url": "https://github.com/kucherenko/jscpd"
}

jscpd

[]!(#backers) []!(#sponsors)

Copy/paste detector for programming source code, supports 150+ formats.

Copy/paste is a common technical debt on a lot of projects. The jscpd gives the ability to find duplicated blocks implemented on more than 150 programming languages and digital formats of documents. The jscpd tool implements Rabin-Karp algorithm for searching duplications.

Packages of jscpd

name	version	description
[jscpd]!(apps/jscpd)		main package for jscpd (cli and API for detections included)
[@jscpd/core]!(packages/core)		core detection algorithm, can be used for detect duplication in different environments, one dependency to eventemitter3
[@jscpd/finder]!(packages/finder)		detector of duplication in files
[@jscpd/tokenizer]!(packages/tokenizer)		tool for tokenize programming source code
[@jscpd/leveldb-store]!(packages/leveldb-store)		LevelDB store, used for big repositories, slower than default store
[@jscpd/html-reporter]!(packages/html-reporter)		Html reporter for jscpd
[@jscpd/badge-reporter]!(packages/badge-reporter)		Badge reporter for jscpd

Installation

$ npm install -g jscpd

Usage

$ npx jscpd /path/to/source

or

$ jscpd /path/to/code

or

$ jscpd --pattern "src/**/*.js"

More information about cli [here]!(apps/jscpd).

Programming API

For integration copy/paste detection to your application you can use programming API:

jscpd Promise API

import {IClone} from '@jscpd/core';
import {jscpd} from 'jscpd';

const clones: Promise<IClone[]> = jscpd(process.argv);

jscpd async/await API

import {IClone} from '@jscpd/core';
import {jscpd} from 'jscpd';
(async () => {
  const clones: IClone[] = await jscpd(['', '', __dirname + '/../fixtures', '-m', 'weak', '--silent']);
  console.log(clones);
})();

detectClones API

import {detectClones} from "jscpd";

(async () => {
  const clones = await detectClones({
    path: [
      __dirname + '/../fixtures'
    ],
    silent: true
  });
  console.log(clones);
})()

detectClones with persist store

import {detectClones} from "jscpd";
import {IMapFrame, MemoryStore} from "@jscpd/core";

(async () => {
  const store = new MemoryStore<IMapFrame>();

  await detectClones({
    path: [
      __dirname + '/../fixtures'
    ],
  }, store);

  await detectClones({
    path: [
      __dirname + '/../fixtures'
    ],
    silent: true
  }, store);
})()

In case of deep customisation of detection process you can build your own tool with @jscpd/core, @jscpd/finder and @jscpd/tokenizer.

Start contribution

• Fork the repo kucherenko/jscpd
• Clone forked version (git clone https://github.com/{your-id}/jscpd)
• Install dependencies (pnpm install)
• Run the project in dev mode: pnpm dev (watch changes and rebuild the packages)
• Add your changes
• Add tests and check it with pnpm test
• Build your project pnpm build
• Create PR

Who uses jscpd

• GitHub Super Linter is combination of multiple linters to install as a GitHub Action
• Code-Inspector is a code analysis and technical debt management service.
• Mega-Linter is a 100% open-source linters aggregator for CI (GitHub Action & other CI tools) or to run locally
• Codacy automatically analyzes your source code and identifies issues as you go, helping you develop software more efficiently with fewer issues down the line.
• Natural is a general natural language facility for nodejs. It offers a broad range of functionalities for natural language processing.

Backers

Thank you to all our backers! 🙏 [Become a backer]

Sponsors

Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [Become a sponsor]

License

[MIT]!(LICENSE) © Andrey Kucherenko