1) What htmx is and Setup
Understand the philosophy behind htmx and get your development environment ready. Learn why hypermedia-driven applications are making a comeback and when htmx is the right choice for your project.
- The origins of htmx and Intercooler.js
- REST and HATEOAS principles
- The role of hypermedia in frontend architecture
- Comparison to JavaScript-heavy approaches
- Use cases where htmx excels
- Project structure and HTML setup
- CDN vs npm installation
- Setting up a local server and dev tools
- Testing the htmx script load
Set up an HTML page with htmx loaded via CDN, create a simple Flask endpoint.
2) Core htmx Attributes & Patterns
Master the fundamental building blocks of htmx—the attributes that transform static HTML into interactive applications without writing JavaScript.
- hx-get, hx-post, hx-put, hx-delete
- hx-target, hx-trigger, and hx-include
- hx-swap and swap modes (innerHTML, outerHTML, afterbegin, etc.)
- Creating backend endpoints
- HTTP method overrides and safety
- Working with hidden inputs and CSRF tokens
- Real-time updates with polling and triggers
- Inspecting requests and responses with dev tools
- Debugging common issues
- Accessibility considerations
Build an interactive todo list with add, delete, and mark-complete functionality.
3) Backend Integration
Learn to create server endpoints that work seamlessly with htmx, with deep focus on Python/Flask patterns that transfer to other backends.
- Python: Flask (light endpoints), Django (forms/templates), CSRF
Build a complete contact form system with Flask backend.
4) Forms and Validation
Master form handling in htmx—from simple submissions to complex multi-step workflows with real-time validation and elegant user feedback.
- Form event lifecycle in htmx
- hx-indicator and spinners
- Error messaging and status elements
- HTML5 validation and custom server responses
- Integrating with backend form validators
Create a multi-field user registration form with real-time validation.
5) DOM Manipulation & Conditional Rendering
Control what users see and when they see it, using server logic to drive UI changes dynamically without client-side JavaScript.
- Inline conditionals using server logic
- DOM fragment targeting
- Lazy loading with hx-trigger on scroll
- Content refresh without user input
Build an infinite-scroll news feed that lazy-loads articles as users scroll down.
6) State and Data Flow
Manage application state and coordinate data between client and server in the htmx paradigm where the server is the source of truth.
- hx-vals, hx-params, and passing state
- Simulating data binding with dynamic values
- Triggering updates on input change, focus, blur, or custom events
- htmx event hooks: htmx:beforeSend, etc.
- Context-aware updates
- Keeping UI in sync with backend data changes
- Linking components without JavaScript routing
Build a shopping cart system.
7) Performance and Testing
Optimize htmx applications for speed and reliability, and implement comprehensive testing strategies to ensure quality.
- Optimize htmx applications for speed and reliability
- Implement comprehensive testing strategies to ensure quality.
- Lazy loading content and images
- Server-side performance tips
- Testing HTML responses
- Debugging with dev tools and htmx events
Take the todo app and optimize it. Write backend unit tests for all endpoints.
8) Building SPAs with htmx
Create single-page application experiences that provide smooth navigation and instant updates without the complexity of traditional SPA frameworks.
- The importance of an SPA
- Page transitions with hx-boost
- Using hx-push-url for history tracking
- Partial loading patterns
- SPA vs MPA tradeoffs
- Linking views together with state
Convert a traditional multi-page blog application into an SPA experience.
9) Deployment and Best Practices
Take your htmx application to production with confidence, following industry best practices for performance, security, and maintainability.
- Hosting options (Vercel, Netlify, Heroku)
- SEO optimization with server-rendered pages
- Accessibility and semantic HTML
- Performance audits
- Bundling and minification tips
Deploy your htmx application to a hosting platform of choice (Heroku or Railway for example).
10) Optional: End-to-End Testing
Implement comprehensive end-to-end testing for htmx applications using Playwright to ensure reliability and catch bugs before production.
- Using Playwright for E2E Testing with htmx
Add Playwright tests to the todo app that verify: adding a todo, deleting a todo, marking complete, and form validation.
11) Optional: UI/UX and Animations
Polish your htmx applications with smooth transitions and professional feedback patterns that make server-driven UIs feel responsive and modern.
- Using CSS transitions with hx-swap and partial updates
- Leveraging hx-indicator for loading animations
- Animating content appearance with opacity, scale, and slide-in effects
- Delaying or staging swaps for animation timing
- Integrating with animation libraries like Animate.css
- Enhancing user feedback with class toggles and conditional states
- Best practices for accessible and non-distracting animations
Enhance the todo app from earlier with animations
12) Optional: Custom Extensions and Alpine.js Integration
Extend htmx's capabilities for edge cases and add lightweight client-side logic when server-driven patterns aren't enough.
- htmx.config and customizing behavior
- Registering an extension
- Overriding request/response handling
- Using Alpine.js for client-side state
- Lightweight two-way interaction
- Integrating third-party JavaScript modules
Create a modal dialog system using Alpine.js for open/close state management.
