PHP_CodeSniffer rules (sniffs) to enforce WordPress coding conventions


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WordPress Coding Standards for PHP_CodeSniffer


This project is a collection of PHP_CodeSniffer rules (sniffs) to validate code developed for WordPress. It ensures code quality and adherence to coding conventions, especially the official WordPress Coding Standards.

Project history

  • In April 2009 original project from Urban Giraffe was published.
  • In May 2011 the project was forked on GitHub by Chris Adams.
  • In April 2012 XWP started to dedicate resources to develop and lead the creation of the sniffs and rulesets for WordPress-Core, WordPress-VIP ( VIP), and WordPress-Extra.
  • In 2015, J.D. Grimes began significant contributions, along with maintenance from Gary Jones.
  • In 2016, Juliette Reinders Folmer began contributing heavily, adding more commits in a year than anyone else in 5 years previous since the project's inception.



The WordPress Coding Standards require PHP 5.3 or higher and PHP_CodeSniffer version 2.9.0 or higher. As of version 0.13.0, the WordPress Coding Standards are compatible with PHPCS 3.0.2+. In that case, the minimum PHP requirement is PHP 5.4.


Standards can be installed with the Composer dependency manager:

composer create-project wp-coding-standards/wpcs --no-dev

Running this command will:

  1. Install WordPress standards into wpcs directory.
  2. Install PHP_CodeSniffer.
  3. Register WordPress standards in PHP_CodeSniffer configuration.
  4. Make phpcs command available from wpcs/vendor/bin.

For the convenience of using phpcs as a global command, you may want to add the path to the wpcs/vendor/scripts (PHPCS 2.x) and/or wpcs/vendor/bin (PHPCS 3.x) directories to a PATH environment variable for your operating system.

Installing WPCS as a dependency

When installing the WordPress Coding Standards as a dependency in a larger project, the above mentioned step 3 will not be executed automatically.

There are two actively maintained Composer plugins which can handle the registration of standards with PHP_CodeSniffer for you:

It is strongly suggested to require one of these plugins in your project to handle the registration of external standards with PHPCS for you.


  1. Install PHP_CodeSniffer by following its installation instructions (via Composer, Phar file, PEAR, or Git checkout).

    Do ensure that PHP_CodeSniffer's version matches our requirements, if, for example, you're using VVV.

  2. Clone the WordPress standards repository:

     git clone -b master wpcs
  3. Add its path to the PHP_CodeSniffer configuration:

     phpcs --config-set installed_paths /path/to/wpcs

    Pro-tip: Alternatively, you can tell PHP_CodeSniffer the path to the WordPress standards by adding the following snippet to your custom ruleset:

    <config name="installed_paths" value="/path/to/wpcs" />

To summarize:

cd ~/projects
git clone phpcs
git clone -b master wpcs
cd phpcs
#PHPCS 2.x
./scripts/phpcs --config-set installed_paths ../wpcs
#PHPCS 3.x
./bin/phpcs --config-set installed_paths ../wpcs

And then add the ~/projects/phpcs/scripts (PHPCS 2.x) or ~/projects/phpcs/bin (PHPCS 3.x) directory to your PATH environment variable via your .bashrc.

You should then see WordPress-Core et al listed when you run phpcs -i.


Standards subsets

The project encompasses a super-set of the sniffs that the WordPress community may need. If you use the WordPress standard you will get all the checks. Some of them might be unnecessary for your environment, for example, those specific to VIP coding requirements.

You can use the following as standard names when invoking phpcs to select sniffs, fitting your needs:

Using a custom ruleset

If you need to further customize the selection of sniffs for your project - you can create a custom ruleset file. When you name this file either phpcs.xml or phpcs.xml.dist, PHP_CodeSniffer will automatically locate it as long as it is placed in the directory from which you run the CodeSniffer or in a directory above it. If you follow these naming conventions you don't have to supply a --standard arg. For more info, read about using a default configuration file. See also provided phpcs.xml.dist.sample file and fully annotated example in the PHP_CodeSniffer documentation.

Customizing sniff behaviour

The WordPress Coding Standard contains a number of sniffs which are configurable. This means that you can turn parts of the sniff on or off, or change the behaviour by setting a property for the sniff in your custom phpcs.xml file.

You can find a complete list of all the properties you can change in the wiki.

Recommended additional rulesets

The PHPCompatibility ruleset comes highly recommended. The PHPCompatibility sniffs are designed to analyse your code for cross-PHP version compatibility. Install it as a separate ruleset and either run it separately against your code or add it to your custom ruleset.

Whichever way you run it, do make sure you set the testVersion to run the sniffs against. The testVersion determines for which PHP versions you will receive compatibility information. The recommended setting for this at this moment is 5.2-7.1 to support the same PHP versions as WordPress Core supports.

For more information about setting the testVersion, see:

How to use

Command line

Run the phpcs command line tool on a given file or directory, for example:

phpcs --standard=WordPress wp-load.php

Will result in following output:

 24 | WARNING | [ ] error_reporting() can lead to full path disclosure.
 24 | WARNING | [ ] error_reporting() found. Changing configuration at runtime
    |         |     is rarely necessary.
 34 | ERROR   | [x] Expected 1 spaces before closing bracket; 0 found
 39 | WARNING | [ ] Silencing errors is discouraged
 39 | WARNING | [ ] Silencing errors is discouraged
 46 | ERROR   | [ ] Inline comments must end in full-stops, exclamation marks,
    |         |     or question marks
 46 | ERROR   | [x] There must be no blank line following an inline comment
 63 | WARNING | [ ] Detected access of super global var $_SERVER, probably
    |         |     needs manual inspection.
 63 | ERROR   | [ ] Detected usage of a non-validated input variable: $_SERVER
 63 | ERROR   | [ ] Missing wp_unslash() before sanitization.
 63 | ERROR   | [ ] Detected usage of a non-sanitized input variable: $_SERVER
 74 | ERROR   | [ ] Inline comments must end in full-stops, exclamation marks,
    |         |     or question marks
 90 | ERROR   | [x] String "Create a Configuration File" does not require
    |         |     double quotes; use single quotes instead
 92 | ERROR   | [ ] Expected next thing to be an escaping function (see Codex
    |         |     for 'Data Validation'), not '$die'
 92 | ERROR   | [ ] Expected next thing to be an escaping function (see Codex
    |         |     for 'Data Validation'), not '__'

Using PHPCS and WPCS from within your IDE

Running your code through WPCS automatically using CI tools

Travis CI

To integrate PHPCS with WPCS with Travis CI, you'll need to install both before_install and add the run command to the script. If your project uses Composer, the typical instructions might be different.

If you use a matrix setup in Travis to test your code against different PHP and/or WordPress versions, you don't need to run PHPCS on each variant of the matrix as the results will be same. You can set an environment variable in the Travis matrix to only run the sniffs against one setup in the matrix.

Travis CI example

language: php

    # Arbitrary PHP version to run the sniffs against.
    - php: '7.0'
      env: SNIFF=1

  - if [[ "$SNIFF" == "1" ]]; then export PHPCS_DIR=/tmp/phpcs; fi
  - if [[ "$SNIFF" == "1" ]]; then export SNIFFS_DIR=/tmp/sniffs; fi
  # Install PHP_CodeSniffer.
  - if [[ "$SNIFF" == "1" ]]; then git clone -b master --depth 1 $PHPCS_DIR; fi
  # Install WordPress Coding Standards.
  - if [[ "$SNIFF" == "1" ]]; then git clone -b master --depth 1 $SNIFFS_DIR; fi
  # Set install path for WordPress Coding Standards.
  - if [[ "$SNIFF" == "1" ]]; then $PHPCS_DIR/bin/phpcs --config-set installed_paths $SNIFFS_DIR; fi
  # After CodeSniffer install you should refresh your path.
  - if [[ "$SNIFF" == "1" ]]; then phpenv rehash; fi

  # Run against WordPress Coding Standards.
  # If you use a custom ruleset, change `--standard=WordPress` to point to your ruleset file,
  # for example: `--standard=wpcs.xml`.
  # You can use any of the normal PHPCS command line arguments in the command:
  - if [[ "$SNIFF" == "1" ]]; then $PHPCS_DIR/bin/phpcs -p . --standard=WordPress; fi

Fixing errors or whitelisting them

You can find information on how to deal with some of the more frequent issues in the wiki.


See CONTRIBUTING, including information about unit testing the standard.