What’s New in PHP 8.3

PHP 8.3

PHP, a widely used open-source scripting language, has been a cornerstone of web development for many years. With each new version, PHP continues to evolve, offering developers more features, improved performance, and enhanced security. The latest version, PHP 8.3, is no exception. Released on November 23, 2023, PHP 8.3 introduces a host of new features, performance upgrades, and deprecations. This article will provide a comprehensive guide to the new features and changes in PHP 8.3, along with step-by-step instructions on how to upgrade to this latest version.

Table of Contents

New Features in PHP 8.3

PHP 8.3 introduces several new features and improvements. Some of the notable ones include:

  • Readonly Amendments

PHP 8.3 introduces improvements to readonly classes. One of the accepted changes is the ability to reinitialize readonly properties while cloning. This addresses a specific edge case: overwriting property values within __clone(), allowing deep cloning of readonly properties.

  • New json_validate() Function

The new json_validate() function is another notable addition. This function validates JSON, enhancing the language’s capabilities in handling JSON data.

  • Stack Overflow Detection

PHP 8.3 adds two new ini directives: zend.max_allowed_stack_size and zend.reserved_stack_size. These directives help detect potential stack overflow situations, improving the robustness of PHP applications.

  • New mb_str_pad Function

PHP 8.3 introduces the mb_str_pad() function, a multibyte string equivalent of str_pad(). This function supports multibyte character encodings like UTF-8, addressing a notable absence among the multibyte string functions.

  • Deprecations in PHP 8.3

PHP 8.3 also deprecates several features, which will be removed in PHP 9. These include passing negative $widths to mb_strimwidth(), the NumberFormatter::TYPE_CURRENCY constant, and unnecessary crypt() related constants.

Installation of PHP 8.3

To install PHP 8.3 on Ubuntu or Debian, follow these steps:

  1. Update your system using sudo apt update.
  2. Add the Ondřej Surý’s PHP PPA to your system using sudo add-apt-repository ppa:ondrej/php.
  3. Update your package cache using sudo apt update.
  4. Install PHP 8.3 and its modules using sudo apt install php8.3 php8.3-cli php8.3-{bz2,curl,mbstring,intl}.
  5. If you’re using Apache, enable PHP 8.3 FPM using sudo a2enconf php8.3-fpm

To install PHP 8.3 on Fedora, RHEL, CentOS, and other systems, follow these steps:

  1. Install the EPEL repository: sudo yum install epel-release.
  2. Install the Remi repository, which provides the latest PHP versions: sudo dnf install
  3. Enable the PHP 8.3 repository: sudo yum-config-manager --enable remi-php83.
  4. Install PHP 8.3: sudo yum install php.

Troubleshooting Tips

When migrating from PHP 8.2.x to PHP 8.3.x, it’s important to test for any incompatibilities before switching PHP versions in production environments. For instance, the change in string to int comparison in PHP 8 has some consequences that could affect your code. Therefore, it’s crucial to thoroughly test your code with the new PHP version before deploying it.


PHP 8.3 is a significant update that brings a host of new features, changes, and deprecations. These updates enhance the language’s performance, security, and developer experience, making PHP an even more robust and efficient tool for web development. By understanding and leveraging these new features, you can write cleaner, more efficient, and more secure PHP code. As always, remember to test your applications thoroughly when upgrading to a new PHP version to ensure compatibility and performance.


r00t is a seasoned Linux system administrator with a wealth of experience in the field. Known for his contributions to, r00t has authored numerous tutorials and guides, helping users navigate the complexities of Linux systems. His expertise spans across various Linux distributions, including Ubuntu, CentOS, and Debian. r00t's work is characterized by his ability to simplify complex concepts, making Linux more accessible to users of all skill levels. His dedication to the Linux community and his commitment to sharing knowledge makes him a respected figure in the field.
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