Oxc React Compiler

The Oxc React Compiler is a rewrite of the React Compiler based on the React team's Rust rewrite. It compiles React.js apps 10x faster than the original Babel implementation, uses less memory, and ships with a more complete implementation and better error handling.

In Vite projects, it's enabled by installing the oxc-transform-react package and turning on the compiler flag:

# shell
pnpm add -D @vitejs/plugin-react@^6.1.0 oxc-transform-react

# vite.config.js
import { defineConfig } from "vite";
import react from "@vitejs/plugin-react";

export default defineConfig({
  plugins: [react({ compiler: true })],
});

Vitest 5

Released in September, Vitest 5 is up to 50% faster than Vitest 4 and cuts test times by double-digit percentages in many common scenarios. Transformed files are shared across projects, modules are cached on disk, and less data moves between the main process and workers.

  • vitest doctor breaks down setup, import, transform, and test time, tests alternative configurations, and recommends faster settings.
  • Trace View records browser interactions, assertions, and DOM snapshots for replaying failures or inspecting them in an HTML report.
  • Conditional mocks with vi.when map arguments to responses without a hand-written mockImplementation.
  • Better benchmarks behave like regular tests, with fixtures, hooks, retries, filters, and assertions.
  • Stricter assertions fail unawaited async assertions, clear mock calls before each test, and add a --repeats flag for tracking down intermittent failures.

tsgolint: type-aware linting, stable

tsgolint, the type-aware linting engine behind Oxlint, is now stable. It catches bugs that need TypeScript type data while running 12 to 18 times faster than ESLint with typescript-eslint — up to 18x in large codebases — and supports 59 of typescript-eslint's 61 type-aware rules.

Because one TypeScript program can be shared across linting and type-checking, Oxlint avoids analyzing the project twice. Both type-aware linting and TypeScript diagnostics are switched on in the Oxlint config:

import { defineConfig } from "oxlint";

export default defineConfig({
  options: {
    typeAware: true,
    typeCheck: true,
  },
});

Oxfmt and Bundled Dev

Oxfmt's JSON, CSS, SCSS, Less, GraphQL, and YAML formatters have been rewritten in Rust, making it 7x faster than Prettier while keeping Prettier-compatible output and ergonomics.

pnpm add -D oxfmt
pnpm oxfmt --migrate prettier
pnpm oxfmt

Work also continues on "Bundled Dev" (formerly Full Bundle Mode), a development mode that runs Vite's production bundler during development and is being shaped by customers with very large web applications.

import { defineConfig } from "vite";

export default defineConfig({
  experimental: {
    bundledDev: true,
  },
});

Bundled Dev is expected to leave experimental status soon; Cloudflare's Dashboard already uses it for all internal developers.

Vite+ 1.0

Speed is one lever; reducing decision fatigue and supplying good defaults is another. Vite+ is now 1.0, bundling VoidZero's tools into a single unified toolchain: Vite 8, Vitest 5, Rolldown, Oxlint, Oxfmt, and task caching.

Layered optimization and the agent era

Developer experience has always meant improving the feedback loop, but optimization now targets agents as well as humans. As inference gets faster, type-checking, linting, and building become the bottleneck again — and every second those take is a second an agent waits before making progress.

Because the VoidZero tools are built on each other, from the compiler (Oxc) to the bundler (Rolldown) to the build tool (Vite), the linter (Oxlint), and the test runner (Vitest), an optimization at one layer flows through to everything above it.

Open source commitments and what's next

The four months since VoidZero joined Cloudflare have produced more than 80 releases and over 1,200 closed issues. Vite, Vitest, Rolldown, Oxc, and Vite+ remain open source, vendor-agnostic, and community-driven.

VoidZero is a member of the Open Source Pledge. Cloudflare committed $1M to a Vite ecosystem fund in the original announcement, followed by an additional $1M commitment to open source.

Planned work includes major improvements to Oxc's parser with up to 3x potential speedup, a re-designed chunking algorithm in Rolldown, and an open-source, self-hostable version of Void, the Vite-native deployment platform built on Cloudflare.