Overview

jscpd is a free, open-source tool for finding duplicated code across a repository. It suits developers who want clone checks in local workflows or CI, with a configurable threshold that can fail a build. Its breadth of language support and reporting options make it flexible, though semantic clone detection remains experimental.

It uses token-based scanning and detects exact clones by default; renamed, near-miss, and semantic detection are opt-in. The project says it supports 224 languages, a useful reach for mixed-language repositories, but dead-code analysis is much narrower.

For a broader comparison, see Code Clone Detection Tools.

Key features

Clone detection and reports

Reports include HTML, JSON, XML, README badges, SARIF, CodeClimate, and OpenMetrics. That gives teams options for human-readable output, badges, and integration with automated code-analysis tools. Exact matching is the dependable default; teams considering semantic matching should treat it as experimental rather than a mature substitute for exact clone checks.

CI and developer workflows

The GitHub Action can scan a repository, enforce a duplication threshold, and upload SARIF results for GitHub Code Scanning. GitLab CI reporters are also documented. Checks can run before commits through the pre-commit framework, Husky, or a shell hook, making it possible to catch duplication earlier than a CI failure.

A built-in MCP server lets Claude, Cursor, and other MCP clients check code for clones, and the project provides agent skills. These integrations may suit teams adding clone checks to AI-assisted coding workflows, while the core threshold and reporting features remain useful without them.

Dashboard and dead-code analysis

One run can produce a dashboard summarizing project size, duplication, complexity, dead code, and a health score. Dead-code coverage is limited to JavaScript, TypeScript, and Python, with Rust support when compiler diagnostics are supplied. That makes the dashboard a useful overview for those languages, not a comprehensive dead-code analyzer for every language jscpd scans.

Pricing

jscpd is free and open source. The jscpd plan costs 0.00 USD per free and is described as an open-source code detector. There is no paid tier identified here, so its cost advantage comes without a trade-off between basic and premium feature sets. Installation options include curl, PowerShell, npm, pip, cargo, Homebrew, Nix, Docker, and npx.

Platforms

jscpd supports Linux, macOS, and Windows, as well as API and self-hosted use. Direct binaries are available for macOS, Linux, and Windows, including x64 and ARM64 variants. Version 5 is a self-contained native binary that does not require Node.js, reducing runtime setup for teams that prefer not to add Node to a machine. Docker installation is also provided.

Who it's for

jscpd is a strong fit for teams that want repository-wide clone detection with threshold enforcement in CI, especially when they need broad language coverage or multiple report formats. Its local CLI and pre-commit options also suit developers who want duplication checks before code reaches a shared branch.

It is less suitable as a single solution for broad dead-code analysis across many languages: that dashboard capability covers only JavaScript, TypeScript, Python, and conditionally Rust. Teams that need dependable semantic-clone detection should also be cautious, since that mode is experimental.

Pros and cons

Pros: Free and open source, with no paid plan barrier to repository scans.
Pros: Supports 224 languages and offers several clone modes, including opt-in renamed and near-miss detection.
Pros: GitHub Action threshold enforcement, SARIF upload, GitLab CI reporters, and pre-commit options support checks at multiple stages.
Pros: Native binaries for major desktop platforms, including ARM64, work without a Node.js runtime in v5.
Cons: Semantic clone detection is experimental, so it is not the right basis for a critical semantic-analysis requirement.
Cons: Dead-code analysis has limited language coverage compared with clone scanning.

Alternatives

PMD is another free, downloadable static code analyzer for Linux, macOS, Windows, and self-hosted use; consider it if a static analyzer better matches the workflow you need.

NiCad is free, MIT-licensed software for the same desktop and self-hosted platforms, but requires OpenTxl 11 or later; choose it if that dependency fits your environment.

Simian Similarity Analyzer is a free, open-source option for Linux, macOS, and Windows.

Duplo is free software under GNU GPL v2 or later, with prebuilt binaries for Alpine Linux, macOS, and Windows; its Alpine binary may suit users who need that platform.

art-dupl is another free option.

QuickDup is free and supports Linux, macOS, and Windows.

semdup is free and supports Linux, macOS, self-hosted, and Windows use.

dcd is free, AGPL-3.0-licensed software for Linux and macOS, with a separate priority-support plan; consider it if that platform range or support option fits your needs.

Verdict

Choose jscpd if you want a free, repository-level clone detector that can enforce duplication limits in CI and report results in formats your tooling can consume. Its broad language support, native binaries, and local-to-CI workflow are compelling strengths. Look elsewhere if broad dead-code coverage or production-ready semantic clone detection is central to your decision.

	jscpd	semdup
Free plan	Yes	No
Free trial	No	No
Paid from	Free	—
Open source	No	No
Platforms	api, Linux, macOS, self-hosted, Windows	Linux, macOS, self-hosted, Windows
Clone detection method	token	semantic
Scan scope	repository	repository
CI integration	Yes	Yes
Self-hosted option	Yes	Yes

jscpd vs semdup

jscpd

semdup