WordPress development covers everything from tweaking a theme template to building custom blocks, plugins and headless front ends on top of the REST API. The platform has changed a lot since the block editor arrived, and the modern stack now mixes classic PHP with JavaScript and React. This overview maps the territory: the main kinds of work, the tools professionals use, the standards that keep code maintainable, and where to go next for each topic.
The building blocks of WordPress development
Almost every WordPress project touches the same few concepts. Learn these first and the rest of the ecosystem makes sense.
- Hooks. Actions and filters let your code run at specific points or modify data without editing core files. They are the foundation of every theme and plugin. Our guide to hooks, actions and filters covers them in depth.
- The data model. Posts, pages and custom post types share the
wp_poststable; metadata, taxonomies, users and options sit in their own tables. Knowing this helps you write efficient queries. - The template system. Classic themes use PHP files and the template hierarchy; block themes use HTML templates made of block markup plus a
theme.jsonfile. - Blocks. Content and, in block themes, entire layouts are made of blocks. Each block has a
block.jsondefinition, an editor interface written in JavaScript, and front-end output that can be static or rendered in PHP. - Roles and capabilities. Permission checks decide who can do what, and they should guard every action your code performs.
The main types of WordPress development work
Theme development
Themes control presentation. New work increasingly means block themes: templates and template parts written as block markup, with colors, typography, spacing and layout defined in theme.json so users can change them in the Site Editor. Classic PHP themes still power many existing sites and remain worth understanding, especially for maintenance work. Start with our theme development guide.
Plugin development
Plugins add functionality: custom post types, integrations, admin screens, blocks, WooCommerce extensions and more. A good rule of thumb is that anything a site should keep after a theme switch belongs in a plugin, not the theme. The plugin development basics article walks through a first plugin.
Block development
Custom blocks are where WordPress development meets modern JavaScript. The official @wordpress/create-block package scaffolds a block plugin with a build setup in one command, and @wordpress/scripts handles bundling. Dynamic blocks render in PHP, which keeps output in sync with data; the Interactivity API, added in WordPress 6.5, gives blocks a standard way to add front-end behavior. See our Gutenberg block development guide and the official Block Editor Handbook.
REST API and headless
The REST API exposes posts, users, media and custom data as JSON, and you can register your own endpoints. It powers the block editor itself, mobile apps, integrations, and headless builds where a separate front end (often a JavaScript framework) consumes WordPress content. Headless adds flexibility but also complexity: previews, SEO, caching and forms all become your responsibility. The REST API tutorial shows the basics.
Setting up a local development environment
Never develop on a live site. A local environment lets you break things safely and work offline. The common options:
| Tool | How it works | Good for |
|---|---|---|
| WordPress Studio | Desktop app from Automattic, no separate server setup | Quick local sites, theme and content work |
| LocalWP | Desktop app with its own server stack | Freelancers juggling many client sites |
| wp-env | Official npm package that runs WordPress in Docker | Plugin and block development, CI testing |
| DDEV and similar | Docker-based, highly configurable | Teams that need parity with production |
| WordPress Playground | WordPress running in the browser via WebAssembly | Instant demos, testing a plugin, reproducing bugs |
Whichever you pick, set WP_DEBUG to true in wp-config.php locally so notices and warnings surface early, and install a debugging plugin such as Query Monitor to inspect queries, hooks and HTTP calls.
Essential WordPress development tooling
WP-CLI
WP-CLI is the command-line interface for WordPress. It installs core, manages plugins and themes, runs search-and-replace on the database, creates users, and lets you execute PHP against a loaded site. Once you are comfortable with it, many dashboard chores take seconds:
wp core download
wp config create --dbname=dev --dbuser=root --prompt=dbpass
wp core install --url=example.test --title="Dev" --admin_user=dev --admin_email=dev@example.test
wp plugin install query-monitor --activate
wp search-replace 'https://old.example' 'https://new.example' --dry-runComposer and npm
Composer manages PHP dependencies and autoloading; some teams also use it to manage WordPress core and plugins as dependencies. npm (or a compatible package manager) handles the JavaScript side, including the @wordpress/* packages for blocks. If your plugin ships Composer libraries, consider prefixing namespaces to avoid clashes with other plugins that bundle the same library.
Version control and deployment
Keep themes and plugins in Git. Commit code, not uploads or the database. Deploy through your host’s Git integration, a CI pipeline, or at minimum SFTP with a clear process, and use a staging site to test changes against real content before they go live.
Testing and quality checks
- PHP_CodeSniffer with the WordPress Coding Standards ruleset flags style issues and many security mistakes, such as unescaped output.
- PHPUnit runs unit and integration tests;
wp-envcan provide the test environment. - The Plugin Check plugin runs the checks used for the wordpress.org plugin directory, and the Theme Check plugin performs similar checks for themes.
- End-to-end tests with a browser automation tool catch editor regressions that unit tests miss.
Coding standards and secure code
The project publishes official WordPress Coding Standards for PHP, JavaScript, CSS, HTML and accessibility. Following them makes your code readable to other WordPress developers and is expected for anything submitted to wordpress.org.
Security deserves its own habits. The core rules are short and non-negotiable:
- Sanitize input with functions such as
sanitize_text_field()andabsint(). - Escape output late, at the point of printing, with
esc_html(),esc_attr(),esc_url()andwp_kses_post(). - Check capabilities with
current_user_can()before doing anything privileged. - Verify nonces on forms and AJAX requests to block cross-site request forgery.
- Use prepared queries via
$wpdb->prepare()whenever SQL includes variable data.
Also prefix your functions, classes, options and hooks with something unique to your project. Name collisions between plugins are one of the most common causes of fatal errors.
Career paths in WordPress development
Because WordPress runs everything from personal blogs to large publishing and commerce sites, there is room for several specializations:
- Theme developer: HTML, CSS, block markup and
theme.json, plus design sense. Commercial theme shops, StepFox included, build and sell block themes this way. - Plugin developer: strong PHP, databases, APIs and security; increasingly React for admin interfaces and blocks.
- Full-stack or agency developer: builds complete client sites, handles hosting, performance and integrations.
- WooCommerce specialist: payments, shipping, custom checkout logic and store performance.
- Headless or enterprise developer: REST or GraphQL APIs, JavaScript frameworks, CI/CD and scaling.
Contributing to WordPress itself, through Trac tickets, Gutenberg pull requests, translations or documentation, is one of the best ways to learn and to build a visible track record. For a closer look at the role, skills and hiring side, read what a WordPress developer does.
Frequently asked questions
Do I need to learn React for WordPress development?
Not for everything. Theme work, PHP plugins and server-side rendering need little or no React. Building custom block editing interfaces or complex admin screens does call for React and the @wordpress component packages.
Is PHP still worth learning?
Yes. WordPress core, plugins and dynamic blocks are PHP. Even JavaScript-heavy projects rely on PHP for registration, data access and rendering.
Should new themes be block themes or classic?
For new projects, block themes are the direction core is moving, and they give site owners visual control in the Site Editor. Classic themes remain fully supported and are the right choice when you maintain an existing classic codebase.
Key takeaways
- WordPress development rests on hooks, the data model, templates, blocks and capabilities.
- The main tracks are themes, plugins, blocks and REST API or headless work, and they overlap.
- Develop locally with Studio, LocalWP, wp-env, DDEV or Playground, never on a live site.
- WP-CLI, Composer, npm, Git and PHP_CodeSniffer form the core professional toolkit.
- Sanitize input, escape output, check capabilities and verify nonces in every project.
Pick one track, build something small and real, and work outward from there.
