Web Component
A set of browser-native APIs for creating reusable, encapsulated custom HTML elements with their own styling and logic.
Web Components are a set of standardized browser APIs that allow developers to create reusable, encapsulated custom HTML elements. The three core technologies are Custom Elements (defining new HTML tags), Shadow DOM (encapsulating styles and markup), and HTML Templates (defining reusable markup structures). Together, they enable creation of elements like <testimonial-carousel> or <review-widget> that work natively in any browser without framework dependencies.
For testimonial widgets, Web Components offer significant advantages. Shadow DOM encapsulation ensures the widget's styles do not leak into or get affected by the host page's CSS — solving one of the most common problems with embedded testimonial widgets. Custom Elements allow embedding with a single intuitive HTML tag, making implementation as simple as writing <testimonial-widget space-id="abc" layout="grid"></testimonial-widget>.
Unlike framework-specific components (React, Vue, Angular), Web Components work everywhere — on static HTML sites, WordPress, Shopify, Webflow, and any JavaScript framework. This universal compatibility makes them ideal for embeddable third-party widgets that need to work on any customer's website regardless of their tech stack.
Web Components can also communicate with the host page through custom events and observed attributes, enabling interactive features like filtering testimonials by tag, changing display layouts, or responding to the host page's theme (dark/light mode).
Best practices for testimonial Web Components include keeping the component lightweight by lazy loading media content, providing sensible defaults while allowing extensive customization through attributes and CSS custom properties, ensuring accessibility through proper ARIA attributes and keyboard navigation, and gracefully handling errors when the testimonial API is unavailable. Progressive enhancement — showing a basic fallback while the component initializes — ensures visitors always see something useful.
Frequently Asked Questions
What is the advantage of Web Components over iframes?
Web Components render as part of the page DOM, providing better SEO indexability, native responsive behavior, and the ability to communicate with the host page. They also eliminate the rigid fixed-height constraint of iframes. However, they require JavaScript to function. Iframes remain simpler for platforms that restrict JavaScript or when complete isolation is preferred.
Do Web Components work in all browsers?
Yes. All modern browsers — Chrome, Firefox, Safari, and Edge — fully support Web Components including Custom Elements, Shadow DOM, and HTML Templates. Legacy browsers like Internet Explorer do not support them, but IE usage has dropped below 1%. For the rare case where support is needed, lightweight polyfills are available.
Related Terms
Related Articles
Build trust.
Drive revenue.
Join thousands of businesses using VideoTestimonials to build trust and accelerate growth.