Xdebug is a step debugger and debugging aid for PHP that provides interactive debugging, stack traces, code profiling, and script execution dumping capabilities.
Xdebug addresses the need for runtime visibility into PHP applications by operating as a PHP extension that intercepts execution flow. It enables step-by-step debugging through integration with IDEs, allowing developers to set breakpoints, inspect variables, and trace code execution. Beyond interactive debugging, the tool offers profiling to identify performance bottlenecks, stack trace generation for error analysis, and the ability to dump full script execution to files for later inspection.
Xdebug suits any PHP development workflow where understanding runtime behavior is valuable, from debugging production issues to optimizing performance-critical code. Installation is straightforward on most Linux distributions through package managers, and also available on macOS and Windows via the PIE installer. The tool requires a supported PHP version and an IDE client that implements the debugging protocol; the documentation lists available clients. Most features must be explicitly enabled through configuration settings, allowing developers to activate only what they need for their workflow.
The project maintains active development with regular commits and pull request activity. The codebase is written in C and requires deep knowledge of PHP internals for contributions, with separate contribution guidance provided for potential developers.
