PHP does not have an internal debugging facility. You can use only external tools to debug PHP code. Here i tried to list down PHP debugging tools, which are extremely useful, but listing down these tools was not enough because you don’t know how to use them so i have compiled those tutorials too.

Here is the list of tools:

PHP Debugging Tools

1. Gubed PHP Debugger

Gubed is a cross platform program to debug PHP scripts.

2. PHP Debug

The basic purpose of PHP_Debug is to provide assistance in debugging PHP code, by “debug” i don’t mean “step by step debug” but program trace, variables display, process time, included files, queries executed, watch variables.

3. 

DBG is a a full-featured php debugger, an interactive tool that helps you debugging php scripts.

4. 

PHP Dyn is PHP Extension to help debugging a PHP script.You can get execution trace of scripts not to need change them.HTTP request parameter can be printed.Argument value of the function call and return value can be printed.

5. 

The Xdebug extension helps you debugging your script by providing a lot of valuable debug information.

5. 

Webgrind is an Xdebug profiling web frontend in PHP5. It implements a subset of the features of kcachegrind and installs in seconds and works on all platforms.

6. 

Debugging a live, running PHP application has never been so easy. It’s a live PHP debugger application for the Mac OS.

7. 

APD is a full-featured profiler/debugger that is loaded as a zend_extension. It aims to be an analog of C’s gprof or Perl’s Devel::DProf.

How To Debug PHP Code

This article shares an elegant, simple, and more maintainable way of debugging Ajax apps via the web browser (more specifically for the Mozilla Firefox browser). You’ll learn the basics of leveraging Firefox in conjunction with Firebug and FirePHP to implement FirePHP libraries on web apps and logging messages in the Firebug console.

How to Debug in PHP

This article breaks down the fundamentals of debugging in PHP, helps you understand PHP’s error messages and introduces you to some useful tools to help make the process a little less painful.

Use XDebug or Zend Debugger to boost your productivity when fixing bugs in PHP applications.

The Xdebug is the extension for PHP that helps debugging PHP scripts by providing a lot of valuable debug information. The debug information includes stack traces and function traces in error messages, memory allocation and protection for infinite recursions.

You can easily debug PHP with PhpED’s PHP Debugger. Setting up your system to debug php scripts can be tricky but PhpED’s Settings Wizard can take care of the majority of the debugging configurations.