Vite vs Rspack vs Webpack 2026: Migration Guide

Three bundlers dominate JavaScript in 2026, but they represent three completely different philosophies. Webpack 5 is the legacy workhorse — still powering millions of production apps, still the go-to when a plugin exists for your edge case, still the only option for certain enterprise constraints. Vite is the new default — fast dev server, native ESM, 40M weekly downloads, powers every modern framework. Rspack is the disruptor — a Rust-rewrite of webpack that claims 5-10x faster builds while keeping the webpack plugin API intact.

Which one you should migrate to — and whether you should migrate at all — depends heavily on what you're coming from and what you need.

TL;DR

New project: Use Vite. It's the ecosystem default, has the best DX, and Vite 8's Rolldown closes the raw speed gap with Rust-based tools. Migrating a large webpack app: Evaluate Rspack first — it can be a near drop-in replacement with 5-10x faster builds, making the migration lower risk than a full Vite rewrite. Keep webpack: When you depend on webpack-specific plugins with no Rspack/Vite equivalent, or when your enterprise CI pipeline has webpack deeply embedded and the ROI doesn't justify the switch.

Key Takeaways

Vite 8 (March 2026) ships with Rolldown replacing Rollup — 10-30x faster production builds, closing the speed gap vs Rspack
Rspack is ~98% webpack plugin API compatible — most webpack configs migrate in hours, not weeks
Webpack 5 weekly downloads: still ~25M — massive install base but no major new features since 2021
Vite: ~40M weekly downloads, ~79K GitHub stars — the ecosystem default since 2022
Rspack: ~10K GitHub stars, rapidly growing — ByteDance-backed, production at scale
HMR performance: Vite ~10-15ms, Rspack ~50-100ms, Webpack ~200-500ms

At a Glance

	Webpack 5	Rspack	Vite 8
Version	5.98+	1.x	8.0
GitHub stars	~65K	~10K	~79K
Weekly downloads	~25M	~3M	~40M
Language	JavaScript	Rust	JavaScript (Rolldown: Rust)
Cold build (500 modules)	~15s	~2s	~0.5s (Rolldown)
HMR	~200-500ms	~50-100ms	~10-15ms
webpack plugin compat	100%	~98%	❌ (different API)
Module Federation	✅ v1+v2	✅ v2 native	✅ via plugin
Tree shaking	Good	Good	Excellent (Rolldown)
ESM output	✅	✅	✅ native
Edge/serverless	❌	❌	✅
Config complexity	High	High (same as webpack)	Low

Webpack 5: Still Running the Show (But Showing Its Age)

Webpack 5 remains the most-installed JavaScript bundler by raw download count. Legacy apps, large enterprise codebases, and anything that predates 2022 is likely still on it. The reasons to stay:

Plugin ecosystem depth: 2,000+ plugins, many with no equivalent elsewhere. If you use html-webpack-plugin, copy-webpack-plugin, mini-css-extract-plugin, webpack-bundle-analyzer, or Module Federation v1, webpack has the deepest support
Maximum configurability: Webpack's config API can model almost any custom build pipeline
Stability: No breaking changes expected — the API is stable and battle-tested

The reasons to leave:

# webpack build times on a real-world Next.js 12 app:
npm run build  # cold: 45-90 seconds
# Hot rebuild: 2-8 seconds
# HMR: 200-800ms

# Developer impact: slow feedback loop kills flow state

Webpack's JavaScript runtime is fundamentally slower than Rust-based alternatives. The configuration overhead that made it powerful also makes it the highest-friction bundler for onboarding new developers.

Stay on webpack if: You have 200+ webpack plugins in your config, Module Federation v1 with complex federation topology, or an enterprise security audit that requires all build tooling to be approved before change.

Rspack: The Fastest webpack Migration Path

Rspack is ByteDance's Rust rewrite of webpack, designed to be a drop-in replacement. The key claim: ~98% webpack plugin API compatibility — most projects can migrate by swapping the bundler package without rewriting configs.

# Migration from webpack to Rspack:
npm install -D @rspack/cli @rspack/core
npm uninstall webpack webpack-cli webpack-dev-server

// rspack.config.js — almost identical to webpack.config.js
const { defineConfig } = require("@rspack/core");

module.exports = defineConfig({
  entry: "./src/index.js",
  output: {
    filename: "[name].[contenthash].js",
    path: path.resolve(__dirname, "dist"),
  },
  module: {
    rules: [
      {
        test: /\.(jsx?|tsx?)$/,
        use: [{ loader: "builtin:swc-loader" }],  // Built-in, no babel needed
      },
      {
        test: /\.css$/,
        use: ["style-loader", "css-loader", "postcss-loader"],  // Same as webpack
      },
    ],
  },
  // Most webpack plugins work as-is:
  plugins: [new HtmlRspackPlugin({ template: "./public/index.html" })],
});

Performance vs webpack (Rspack team benchmarks):

Cold build comparison (10,000 module app):
webpack 5:     ~120s
Rspack:        ~15s   (8x faster)

HMR comparison:
webpack 5:     ~300ms
Rspack:        ~80ms  (4x faster)

Build output quality:
webpack:       Mature, battle-tested output optimization
Rspack:        Comparable, improving rapidly

What's compatible:

babel-loader → use builtin:swc-loader instead (faster, no config needed)
css-loader, style-loader, postcss-loader — direct compatibility
html-webpack-plugin → HtmlRspackPlugin (built-in, API-compatible)
copy-webpack-plugin → CopyRspackPlugin (built-in)
mini-css-extract-plugin → CssExtractRspackPlugin (built-in)
Most community plugins: test case-by-case; ~90% work without modification

Module Federation v2: Rspack ships Module Federation v2 as a first-class feature — improved type safety, runtime sharing, and better multi-version handling. If you're on MF v1, migrating to Rspack + MF v2 is the recommended upgrade path.

Who's using Rspack: ByteDance (100,000+ internal modules), plus Shopify, Alibaba, and teams migrating large React/Vue SPAs.

Choose Rspack when: You have a large webpack codebase and want 5-10x faster builds without the risk of a full Vite rewrite. The compatibility story is strong enough to make this a low-risk migration.

Vite 8: The New Default

Vite's approach is fundamentally different from webpack/Rspack. In development, it serves native ES modules directly — no bundling at all. The browser loads modules on-demand, and esbuild pre-bundles dependencies. The result: startup in milliseconds instead of seconds.

// vite.config.ts — significantly simpler than webpack
import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'

export default defineConfig({
  plugins: [react()],
  // That's often the entire config for a React app
  // Compare to 100+ line webpack.config.js
})

# Vite dev server startup (1,000 module React app):
vite:     ~400ms to first page load (modules loaded on demand)
webpack:  ~15s (full bundle before serving)
rspack:   ~3s

# Vite production build (Vite 8 with Rolldown):
vite build:  ~0.5s   (was ~4s with Rollup in Vite 7)
rspack:      ~2s
webpack 5:   ~15s

Vite 8 + Rolldown changes the calculus. Previously, Vite's dev speed was exceptional but production build speed (using Rollup) lagged behind Rspack. Rolldown in Vite 8 closes this gap — matching Rspack in production build speed while keeping Vite's superior dev server experience.

Vite's weaknesses:

No webpack plugin compatibility — all plugins must be Vite/Rollup API
Less control over chunk splitting for complex multi-entry builds
Module Federation support via @originjs/vite-plugin-federation — functional but less mature than native webpack/Rspack MF

Migrating webpack → Vite (difficulty: Medium)

// Key changes needed:
// 1. CommonJS → ESM imports
require('./styles.css')           // → import './styles.css'
const path = require('path')      // → import path from 'path'

// 2. process.env → import.meta.env
process.env.REACT_APP_API_URL     // → import.meta.env.VITE_API_URL

// 3. index.html becomes the entry point (not webpack entry config)
// 4. .js extensions for JSX → .jsx

// Most other config moves to vite.config.ts

Choose Vite when: Starting a new project, building with React/Vue/Svelte/SolidJS (all have official plugins), prioritizing developer experience, or building for edge/serverless environments.

The Migration Decision Tree

Are you starting a new project?
  → Yes: Use Vite. Done.

Are you on webpack with <50 plugins?
  → Consider Rspack first (low migration risk, large speed gain)
  → Then evaluate if Vite's DX is worth the rewrite

Are you on webpack with >50 custom plugins?
  → Rspack is the safer bet (98% API compat)
  → Full Vite migration would require rewriting each plugin

Do you use Module Federation heavily?
  → Rspack (MF v2 native) or webpack (MF v1/v2)
  → Vite MF support is functional but less mature

Do you need edge runtime (Cloudflare Workers, Deno)?
  → Vite only. webpack/Rspack produce Node.js-targeted bundles.

Is your team already on webpack and builds are acceptable?
  → No immediate pressure to migrate
  → Consider Rspack as an upgrade with minimal code changes

Speed Comparison Summary

Build scenario: Large SPA, 5,000 modules, React, TypeScript, CSS Modules

                Cold Build   Hot Rebuild   HMR      Dev Start
Webpack 5:      ~60s         ~8s           ~400ms   ~20s
Rspack:         ~8s          ~1.5s         ~80ms    ~5s
Vite 8 (dev):   N/A          N/A           ~12ms    ~500ms
Vite 8 (prod):  ~3s          ~1s           N/A      N/A

Winner (dev DX):    Vite
Winner (migration): Rspack
Winner (overall):   Vite for new projects, Rspack for webpack migrations

Compare Vite, Rspack, and webpack package health on PkgPulse.