Technical Research and Project Implementation of Svelte in Front‑end Development

Author: Shuan Feng, senior front‑end engineer at Ctrip, focuses on performance optimization, low‑code and Svelte.

Technical Research

Svelte has become a new favorite front‑end framework, created by Rich Harris (author of Ractive, Rollup, Buble). It compiles components to pure JavaScript, eliminating the need for a runtime and reducing bundle size dramatically (≈1/4 of Vue, 1/20 of React).

Key characteristics listed on the official site are:

Write less code

No virtual DOM

Truly reactive

Write less code

Svelte requires fewer lines to achieve the same functionality.

No virtual DOM

Unlike Vue and React, Svelte does not use a virtual DOM; it updates the real DOM directly, avoiding the diff algorithm overhead.

Truly reactive

Svelte’s reactivity is based on compile‑time analysis and direct assignments, unlike the runtime setState or useState patterns.

Project Implementation

The team built a mask‑machine H5 page to validate Svelte in a marketing scenario. The project started from svelte-webpack-starter with TypeScript, SCSS, Babel and Webpack 5, later switched to Vite for faster dev server startup.

Component Structure

Svelte components combine <script> , markup and <style> in a single file; styles are scoped to the component.

Lifecycle

Important lifecycle hooks are onMount , onDestroy , beforeUpdate and afterUpdate , analogous to React’s useEffect .

State Management

Svelte provides a built‑in store API (e.g., writable ) for cross‑component communication without external libraries.

Routing

Community routers such as svelte-routing and svelte-spa-router fill the gap of an official router.

UI and Testing

Existing React UI libraries are not directly usable; the team evaluated Svelte‑Material‑UI and Carbon Components Svelte but ended up writing a few custom components. Unit tests were written with @testing-library/svelte , similar to React testing.

Performance Optimizations

Switching to WebP images, lazy loading, and meta‑tag adjustments improved Lighthouse scores for Performance, Accessibility and SEO.

Practice Summary

Svelte offers a lightweight, compile‑time approach that yields small bundle sizes and fast rendering, making it ideal for marketing pages and Web Components. Its ecosystem is still maturing, but the performance benefits are compelling.

References

Links to comparative articles and community discussions are listed.