Suggestions appear as you type. Use the up and down arrows to choose one and Enter to open it.

This page's audience our own tag's counts — open to see them
–Visits
–Page views
–Clicks to vendors
–Time on page
–Reading now
Clicks to vendors, by tool
  • –
Top countries
  • –
Devices
  • –

– · visits, page views and clicks counted by our own tag, which counts more than our checked analytics; every figure rounded down · how we count

Head-to-head · Code Duplication Detection Tools

JPlag vs Simian Similarity Analyzer

  • Updated Oct 2026
  • Both researched from official sources
  • 6 checks side by side
Higher score JPlag #6 in Code Duplication Detection Tools 6.7/10 Free plan Free plan✓ 2 of 4 features Visit JPlag
Simian Similarity Analyzer #7 in Code Duplication Detection Tools 6.6/10 Open source Free plan✓ 3 of 4 features Visit Simian

JPlag leads on 1 check, Simian Similarity Analyzer on 1, and 4 are even. Who comes out ahead on the 6 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreJPlag · 6.7/10
  • Free planboth
  • Most featuresSimian Similarity Analyzer · 3 of 4

JPlag scores higher on our rubric for code duplication detection tools: 6.7 against 6.6 out of 10; our editors rank them #6 and #7.

JPlag leads on supported languages: 20 versus 19. On ci/pr reporting, Simian Similarity Analyzer gives you Ci where JPlag offers None. Simian Similarity Analyzer offers duplication gates; JPlag doesn't.

JPlag is the better fit for academic or multi-language similarity analysis. Simian Similarity Analyzer is the better fit for broad-language duplicate checks in build pipelines.

  • JPlag fits best

    Academic or multi-language similarity analysis

  • Simian Similarity Analyzer fits best

    Broad-language duplicate checks in build pipelines

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.

Side by side

Feature JPlag 6.7/10 Visit ↗ Simian Similarity Analyzer 6.6/10 Visit ↗
At a glance
Editor score 6.7 6.6
Ranking #6 in Code Duplication Detection Tools #7 in Code Duplication Detection Tools
Best for Academic or multi-language similarity analysis Broad-language duplicate checks in build pipelines
Pricing model Free Free
Starting price Free plan Open source
Free plan ✓ ✓
Free trial — —
Deployment Self-hosted Self-hosted
Platforms Windows, macOS, Linux Windows, macOS, Linux
Support Community Email, Community, Docs
Integrations 1 integrations 1 integrations
Built for Small business, Mid-market, Enterprise Solo, Small business, Mid-market, Enterprise
Features JPlag 2/4 · Simian Similarity Analyzer 3/4
Near-duplicate detection ✓ ✓
Duplication gates — ✓ (best)
Trend visualisation — —
Open-source option ✓ ✓
Specs
Supported languages 20 (best) 19
CI/PR reporting None Ci
Our review
Pros
  • Syntax-aware matching across 20 supported languages
  • Handles some obfuscation and code modifications
  • Free, open source, with CLI and Java API access
  • Supports 19 languages and near-duplicate matching
  • Configurable thresholds plus include and exclude file filters
  • Gradle and build-pipeline integration with duplication failure gates
Cons
  • Focused on pairwise analysis rather than duplication gates
  • No CI pull-request reporting or trend visualisation
  • Self-hosted setup relies on community support
  • Command-line workflow may not suit teams seeking a visual interface
  • No trend visualisation is provided
  • Self-hosted deployment requires teams to manage the runtime
Our verdict

JPlag is a free, open-source tool that compares programs pairwise to identify source-code similarity. It is primarily suited to programming education, where instructors review student submissions, and it can also help examine duplicated…

Read the review →

Simian Similarity Analyzer is an open-source, language-agnostic command-line tool for finding duplicated blocks in source code and other human-readable files. It is aimed at teams that need duplicate checks across large codebases, from…

Read the review →
  1. JPlagCode Duplication Detection Tools 6.7Free plan
  2. Simian Similarity AnalyzerCode Duplication Detection Tools 6.6Open source

Strengths and trade-offs

  • JPlag — where it wins

    • Syntax-aware matching across 20 supported languages
    • Handles some obfuscation and code modifications
    • Free, open source, with CLI and Java API access

    Where it doesn't

    • Focused on pairwise analysis rather than duplication gates
    • No CI pull-request reporting or trend visualisation
    • Self-hosted setup relies on community support

  • Simian Similarity Analyzer — where it wins

    • Supports 19 languages and near-duplicate matching
    • Configurable thresholds plus include and exclude file filters
    • Gradle and build-pipeline integration with duplication failure gates

    Where it doesn't

    • Command-line workflow may not suit teams seeking a visual interface
    • No trend visualisation is provided
    • Self-hosted deployment requires teams to manage the runtime
  • JPlag6.7/10 · Free plan

    A free, syntax-aware tool for pairwise program-similarity analysis across 20 languages.

    Visit JPlagFull verdict →
  • Simian Similarity Analyzer6.6/10 · Open source

    A configurable, language-agnostic duplicate checker for build pipelines.

    Visit SimianFull verdict →

More comparisons

All code duplication detection tools comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update