PHP 7.3

PHP 7.3 built incrementally on PHP 7.2, adding trailing commas in function and method calls, flexible Heredoc and Nowdoc syntax, JSON exception handling through JSON_THROW_ON_ERROR, array destructuring via list() references, and improved handling for PCRE regular expressions. It also introduced is_countable(), array_key_first(), and array_key_last(), deprecated several older features and behaviors, and updated bundled components including OpenSSL and PCRE. The cycle retained the PHP 7 language and runtime model, so most PHP 7.2 applications could move to it with targeted compatibility testing rather than a full rewrite.

PHP 7.3 has reached end of life, so upstream no longer provides security fixes or bug fixes for the runtime. A newly discovered PHP, OpenSSL integration, PCRE, or bundled-library vulnerability may therefore remain unpatched unless an operating-system vendor or commercial provider independently backports a fix. Staying on 7.3 also increasingly constrains dependency upgrades: current versions of frameworks, CMS platforms, libraries, testing tools, and Composer packages commonly require newer PHP versions. The longer an application remains on 7.3, the more its code, dependencies, build images, and deployment environment can diverge from supported versions, making the eventual upgrade broader and riskier.

Inventory every runtime that executes PHP, including web workers, CLI jobs, queue consumers, scheduled tasks, containers, extensions, and development environments. Identify the currently supported PHP target accepted by the application’s framework, CMS, hosting platform, and critical extensions; for most teams, select a maintained current PHP line rather than making PHP 7.3 an intermediate destination. Update Composer constraints and lock files in a separate branch, use static analysis and automated tests to find compatibility issues, and review PHP migration guidance for each version crossed. Pay particular attention to deprecated behavior removed in later releases, stricter type handling, changes in error reporting, dynamic properties, string and array edge cases, and extension availability. Test representative production traffic and background workloads in a staging environment, deploy gradually with monitoring and a rollback plan, then remove PHP 7.3 images and packages from supported build and deployment paths.