Theme Check is a powerful plugin for WordPress developers that analyzes a given theme’s code and offers areas it can be improved upon. It makes sure your theme adheres to the recommendations set forth by WP (or at least it warns you when it is not).
Once you install Theme Check on your website, its link shows up under “Appearance” section in the back-end. Just choose the theme that you want to analyze from the appropriate drop-down box, and this script does the rest. Theme Check displays warnings, required, recommended, and info items to give you an idea how much work you need to put in to optimize your code. You do have the option to suppress the info section.
Not surprisingly, you should start with the required items and work your way through warnings to find immediate issues that need to be fixed in your theme. The recommended section gives you a hand keeping up with the best practices. The info section could be very eye opening if you have not been paying attention to the quality of your code.
Theme Check is a useful tool for any developer interested in developing super clean code. It is fast and gives you a ton of useful nuggets for your theme development endeavors.