semdup review
A self-hosted semantic clone detector with repository diff and CI support.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
semdup is an open-source command-line tool for identifying near-duplicate source code by comparing semantic meaning rather than token sequences. It indexes functions or code blocks, stores embeddings locally, and reports duplicate clusters across repositories. Developers can configure similarity thresholds and minimum cluster sizes, view source snippets, and use repository diff mode for pull-request review. It supports Rust, TypeScript, Python, Go, Java, C#, PHP, Ruby, C, and C++.
The deployment model is self-hosted and installed locally, which suits teams that want code analysis to remain within their own environment. Local ONNX inference can run on CPU or CUDA, while an optional Amazon Bedrock embedding backend provides another processing path. Bedrock usage may incur separate AWS charges, so teams choosing that backend should account for infrastructure costs beyond the open-source software itself. The local option is the clearer fit for users prioritizing control over where embeddings are generated and stored.
For repository workflows, semdup includes a GitHub Actions workflow and action, making automated scans and pull-request-oriented review part of its supported setup. Its semantic approach is useful when copied code has been renamed, reorganized, or changed beyond straightforward token similarity. The trade-off is focus: this is a self-hosted, command-line tool centered on repository-level duplicate detection rather than a broader hosted code-quality platform. Choose semdup when semantic matching, configurable clustering, local inference, and CI integration are priorities; consider an alternative if you need a hosted service or coverage beyond its supported languages.
semdup pros and cons
- Where it wins
- Finds semantic duplicates beyond token-level similarity
- Supports local CPU or CUDA inference with ONNX
- Automates repository scans through GitHub Actions
- Where it doesn't
- Self-hosted installation adds deployment responsibility
- Amazon Bedrock embeddings may incur separate AWS charges
- Language support is limited to the listed programming languages
semdup fact sheet, pricing and score →
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update