---
title: PMD Documentation website
keywords: java
permalink: index.html
toc: false
summary: >
    Welcome to PMD, an extensible cross-language static code analyzer.
    It finds common programming flaws like unused variables, empty catch blocks, unnecessary object creation,
    and so forth. Additionally it includes CPD, the copy-paste-detector. CPD finds duplicated code.
last_updated: August 2017
author: Jeff Jensen <jjensen@apache.org>, Andreas Dangel <andreas.dangel@adangel.org>
---


<!-- ## Welcome to PMD! -->

<!-- First time user? Then you may be interested in our [quickstart series](TODO)! -->

<br/>


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<div class="col-lg-12">
    <h2 class="page-header">Welcome to PMD!</h2>
</div>


<div class="filter-options">
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      <button class="btn btn-primary" data-group="getting_started">Getting Started</button>
      <button class="btn btn-primary" data-group="userdocs">User documentation</button>
      <button class="btn btn-primary" data-group="extending">Extending PMD</button>
      <button class="btn btn-primary" data-group="contributing">Contributing</button>
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       tags="getting_started"
       datagroups='["getting_started"]'
       description="These pages summarize the gist of PMD usage to get you started quickly."
       title="Getting started" %}


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       tags="rule_references"
       datagroups='["userdocs"]'
       title="Rule references"
       description="Pick your language to find out about the rule it supports."
       image="fa-database"
       titlemaker="page.language_name" %}

    {% include custom/shuffle_panel.html
       tags="userdocs,extending"
       datagroups='["userdocs", "extending", "contributing"]'
       title="Writing rules"
       description="These pages document the process of writing and testing custom rules and metrics for PMD."
    %}

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       tags="userdocs"
       except_tags="extending,tools"
       datagroups='["userdocs"]'
       image="fa-cog"
       title="Usage and configuration"
       description="Learn how to build effective and versatile rulesets."
    %}


    {% include custom/shuffle_panel.html
       tags="devdocs"
       except_tags="extending"
       datagroups='["contributing"]'
       image="fa-github"
       title="Contributing"
       description="If you'd like to help us build PMD, these topics may interest you. See you around!"
    %}



    {% include custom/shuffle_panel.html
       tags="tools"
       datagroups='["userdocs"]'
       title="Tools and integrations"
       description="These pages describe solutions that integrate PMD within your build process."
    %}

    {% include custom/shuffle_panel.html
       tags="devdocs,extending"
       datagroups='["contributing","extending"]'
       title="Major contributions"
       description=""
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</div>

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