Four months of VoidZero at Cloudflare: making the open-source JavaScript toolchain faster for all humans and agents

When VoidZero joined Cloudflare four months ago, we made a commitment to open source, promising that Vite, Vitest, Rolldown, Oxc, and Vite+ will stay open source, vendor-agnostic, and community-driven.  As part of Cloudflare’s Birthday Week, where Cloudflare gives back to the Internet, we thought it’d be a good time to check in on how we’ve been doing against this commitment.

In the four months since VoidZero joined Cloudflare, we’ve shipped more than 80 releases, closed over 1,200 issues, and landed some big performance improvements, including:

• Oxc React Compiler, released in August, compiles React.js apps 10x faster
• Vitest 5, released in September, is up to 50% faster than Vitest 4
• tsgolint is now stable, and is up to 18x faster than ESLint in large codebases
• Oxfmt’s JSON, CSS, SCSS, Less, GraphQL, and YAML formatters are now written in Rust, making it 7x faster than Prettier

On top of this, Vite+, which unifies the entire toolchain with a set of great defaults, is now 1.0. And we’re making progress towards shipping “Bundled Dev” (f.k.a. Full Bundle Mode) — a new development mode that has been shaped by working with customers with massive web applications, including Cloudflare’s own dashboard. By being part of Cloudflare, our engineering team gets a much better view into scenarios that only occur in massive codebases.

VoidZero’s mission is to make the next generation of JavaScript developers more productive than ever before. And in 2026, that means making developers’ agents faster.

A faster developer experience for humans and agents

Developer experience and performance were always about improving the feedback loop while creating software. But now when we optimize for developer experience, we no longer just optimize for humans — we optimize for agents. And as inference gets faster, the speed of type-checking, linting, or building the code becomes the bottleneck again. The longer those processes take, the longer an agent has to wait before making progress and completing its goals.

VoidZero has always been focused on performance, but this new era of software has given us even more reason and motivation to make the entire toolchain faster for both agents and humans. And since the tools in the VoidZero toolchain 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), any optimization at one layer automatically benefits everything built on top.

Oxc React Compiler — 10x faster compile times for React.js apps

We’ve recently shipped the Oxc React Compiler, a rewrite of the React Compiler, based on the React team’s rewrite in Rust. It is 10x faster than the original Babel implementation, uses less memory, and has a more complete implementation with better error handling. If you use Vite, you can enable the Oxc React Compiler by installing the oxc-transform-react package and enabling 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 — up to 50% faster than Vitest 4

Vitest 5, released in September, cuts test times by double-digit percentages across many common scenarios.

• Faster test runs. Vitest shares transformed files across projects, caches modules on disk, and sends less data between its main process and workers.
• vitest doctor. It breaks down setup, import, transform, and test time, then tests other configurations and recommends faster settings.
• Trace View. It records browser interactions, assertions, and DOM snapshots, so you can replay failures or inspect them in an HTML report.
• Conditional mocks with vi.when. Map arguments to responses without writing a manual mockImplementation.
• Better benchmarks. Benchmarks now work like regular tests, with fixtures, hooks, retries, filters, and assertions.
• Fewer false passes. Vitest fails unawaited async assertions, clears mock calls before each test, and adds the --repeats flag to help find intermittent failures.

tsgolint — now stable, up to 18x faster than ESLint in large codebases

tsgolint, the type-aware linting engine behind Oxlint, is now stable. It catches bugs that require TypeScript type data while running 12 to 18 times faster than ESLint with typescript-eslint.

• 59 type-aware rules. tsgolint now supports 59 of typescript-eslint's 61 type-aware rules.
• One pass for linting and type-checking. Oxlint can share one TypeScript program across both tasks instead of analyzing the project twice.

Enable type-aware linting and TypeScript diagnostics in your Oxlint config:

import { defineConfig } from "oxlint";

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

Oxfmt — 7x faster than Prettier with formatters now written in Rust

Oxfmt brings the speed of the Oxc toolchain to formatting. We rewrote its JSON, CSS, SCSS, Less, GraphQL, and YAML formatters in Rust, making Oxfmt many times faster than Prettier, while keeping Prettier-compatible output and ergonomics.

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

Bundled Dev — faster dev server for larger apps

We’ve made progress towards shipping “Bundled Dev” (f.k.a. Full Bundle Mode), which uses Vite’s production bundler during development. This should lead to significant dev server speed-ups in larger applications and reduce network overhead when working with remote sandboxes.

import { defineConfig } from "vite";

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

We’re looking forward to bringing Bundled Dev out of experimental status soon. Cloudflare’s Dashboard already uses Bundled Dev for all internal developers.

Vite+ is now 1.0 — a unified toolchain

Speeding up tools is one way of making humans and agents ship software faster. Another way is by reducing decision fatigue (“Which linter shall I use?”) and providing great defaults. We are excited to announce that Vite+ is now 1.0. Vite+ bundles all of VoidZero’s tools together into a single unified and fast toolchain.

Vite+ ships with Vite 8, Vitest 5, Rolldown, Oxlint, Oxfmt and task caching built in, and comes with great defaults. Check out the Getting Started guide to try it out today.

Cloudflare’s Open Source Investment

VoidZero was born in open source, and we believe a more sustainable open-source ecosystem benefits everyone. VoidZero is a proud member of the Open Source Pledge and as part of Cloudflare, we have the opportunity to expand that impact.

Cloudflare committed $1M to a Vite ecosystem fund to support maintainers and contributors in the original announcement. Since then, Cloudflare has committed an additional $1M to open source. Together, we’re doubling down on open source.

The open-source toolchain for the entire JavaScript community

There is more to come! Features we plan to ship in the next few months include 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 top of Cloudflare. Cloudflare and VoidZero both recognize our responsibility that we have to developers, and we do not take the community’s trust in us for granted. We’re in this for the long haul.

We are excited to keep shipping faster tools, and will continue to make every decision with the community in mind, just like we did when raising venture capital, or when we open sourced Vite+, or when we joined Cloudflare. Thank you for continuing to trust us with your projects and apps, supporting us, and building with us.