What’s the difference between interactivity (CSS) and AMP actions?

CSS-based interactivity uses techniques like :hover states, checkbox hacks, and CSS animations to create visual effects within email. These are purely cosmetic. They ucan show/hide content, animate elements, or create tabbed interfaces, but they cannot communicate with servers or persist data. When the email is closed, any state changes are lost. CSS interactivity works across more email clients and requires no special registration.

AMP actions are fundamentally different: they enable real server communication. AMP can fetch live data via XHR requests, submit form data to your backend, and receive responses that update the email content. This enables actual transactions: submitting a survey response that's recorded in your database, RSVPing to an event that updates your registration system, or browsing a product catalog with live inventory. State persists beyond the session.

Choose CSS interactivity for visual engagement: image carousels, accordion content, hover effects. Choose AMP for functional engagement: forms that submit, content that updates, actions that persist. Many emails benefit from CSS interactivity without needing AMP's complexity; reserve AMP for use cases that genuinely require server communication. CSS makes emails feel interactive; AMP makes emails actually interactive, but that power comes with significantly higher implementation costs.