Why We Chose Svelte Over Vue 3: A Real‑World Migration Case Study

Why Migrate?

Sophie, a UI/UX designer and frontend developer, explains that the migration was driven by Vue 2's upcoming end‑of‑life, the desire for better developer experience, stronger type checking, improved performance, and shorter build times. React was dismissed due to its steep learning curve and lack of out‑of‑the‑box solutions.

Performance Comparison

Vue's author created a GitHub repository to compare Svelte and Vue 3 using the TodoMVC benchmark. Results show:

Svelte single‑file components are about 70% larger than Vue 3 components in normal mode and 110% larger in SSR mode.

If an application contains more than roughly 19 TodoMVC‑sized components (13 in SSR), Svelte's bundle size surpasses Vue's.

Repository: https://github.com/yyx990803/vue-svelte-size-analysis

Why Choose Svelte?

Higher Retention Rate – Survey data shows Svelte ranks second in framework retention over the past five years, while Vue ranks fourth.

Better Type System – Svelte offers a simpler component design flow and built‑in typed events, providing a more human‑friendly type experience.

Global Access Control – Svelte allows importing enums directly into templates, a feature Vue 3 lacks.

Simpler Syntax – Svelte's syntax is more concise and elegant compared to Vue.

Svelte Example

<script>
    let firstName = "";
    let town = "";
    $: fullName = "Full name: " + firstName + ' ' + lastName;
    const reset = () => {
        firstName = "";
        lastName = "";
    }
</script>
<main>
    <div>
        <label>First name</label>
        <input type="text" bind:value={firstName}>
        <label>Last name</label>
        <input type="text" bind:value={lastName}>
        <button on:click={reset}>Reset</button>
    </div>
    <div>{fullName}</div>
</main>
<style>
  main{background-color: white;}
</style>

Vue Example

<template>
  <main>
    <label>First name </label>
    <input type="text" v-model="firstName"/>
    <label>Last name </label>
    <input type="text" v-model="lastName"/>
    <div>Full name: {{fullName}}</div>
    <button @click="handleReset">Reset</button>
  </main>
</template>
<script setup>
import { ref, computed } from 'vue'
const firstName = ref('')
const lastName = ref('')
const fullName = computed(() => firstName.value + " " + lastName.value)
function handleReset() { firstName.value = ""; lastName.value = "" }
</script>
<style scoped>
  main{background-color: white;}
</style>

No Extra HTML Wrapper – Svelte lets developers write plain HTML without an additional <template> block.

Scoped Styles by Default – Each component's styles are automatically scoped, preventing unintended CSS leakage.

Automatic Updates – Declared variables trigger UI updates instantly, eliminating the need for computed properties.

Shortcomings – Svelte's community is smaller because it was launched in 2019, but it is growing rapidly with regular releases.

Migration Method

Timeline : The team migrated in August when traffic was low.

Duration : Two weeks to convert all files from Vue to Svelte.

Team Size : Three developers (two full‑time on migration, one part‑time for a week).

Workflow : Tasks were split into tickets, new components were built in Storybook, then each developer rewrote their assigned pages in Svelte.

Svelte Kit’s file‑based routing, built‑in layout integration, and Vite bundler provided a smoother developer experience.

Benefits Observed

Higher performance and smoother user experience due to smaller bundle size and no virtual DOM.

Improved developer experience with Vite and faster code execution.

SSR support ensures the app works even without JavaScript.

Cleaner, more maintainable code by co‑locating HTML, JS, and CSS.

Robust type checking eliminated noisy Sentry alerts.

The team is satisfied with the migration, noting faster feature delivery on the Escape platform and a better overall developer experience.