Here’s a list of the developer-oriented plugins for WordPress that I use on a regular basis. (Alternative title: 10 WordPress Plugins You Can’t Live Without. You’ll Never Believe What Number 4 Does!)
Invaluable if you’re working with rewrite rules. Not only lists all the current rewrite rules on your site, but also lets you query a URL to see which rules it matches.
This plugin is an under-appreciated gem. It lets you specify simple tests for your rewrite rules to avoid problems such as missing or clashing rules. Just give it an array of paths and the expected corresponding query for each, and the plugin will let you know if any of them fail.
My own plugin which provides debugging and performance information on database queries, hooks, conditionals, HTTP requests, redirects, scripts & styles, transients, and lots more. A modern-day replacement for Debug Bar.
Deprecated notices in WordPress can slip by, especially if they’re happening some place that you don’t look. This plugin logs these notices and provides a simple admin list screen with the call count and information about the alternative function or function arguments.
Pig Latin and RTL Tester
Combined, these plugins allow you to test your internationalisation implementation and support for right-to-left languages. Bear in mind that you’ll need to be running a built version of WordPress (ie. not from
src) in order to use RTL Tester.
My plugin for swapping between user accounts in WordPress at the click of a button. Instantly switch to your desired user, and instantly switch back when you’re done.
Working with asynchronous events in the WP-Cron system can be challenging sometimes. WP Crontrol shows you pending events, available schedules, and alerts you if WP-Cron can’t spawn on your site for any reason.
A relatively new plugin, this is super handy for anyone building a site that will be served over HTTPS. It uses Content Security Policy reporting to log all mixed content on your site, and provides an admin screen listing the violations.
Provides a UI to manage your site’s transients. You can view, search, edit, and delete transients at will.
Adds some developer-focused logging to the Simple History plugin, such as email logging, 404 logging, and HTTP API logging.
Logs every email sent through WordPress and provides a UI where you can view them.