Getting started

uf compared

The one-screen version

Two rows in that table decide most of the question. If you write TypeScript, the syntax row is worth nothing to you and every other row is a downgrade. If you need the production-server row, uf cannot serve you at all yet.

Read the losses first

What uf does not do is the complete version of that list, sorted into refusals and gaps.

Against create-react-app

CRA is the honest ancestor: an all-in-one tool that hid a build behind one dependency. React deprecated it in February 2025 and recommends a framework or a build tool instead.

What uf takes from it: the shape. One command, no configuration to copy, a project that runs before you have made a single decision.

What uf takes from its failure: everything in docs/red-lines.md. CRA's three failures were an eject cliff with a one-way door, a single package serialising every upgrade in the ecosystem, and solving the build and stopping. uf answers the first with a continuum and no eject, the second by owning orchestration rather than implementation, and the third by being a framework as well — which is the one of the three uf has not finished.

What CRA still has that uf does not: a decade of tutorials that assume it, and the fact that it runs on stable, published, installable software.

Against Vite + React

This is the closest comparison and the least adversarial one, because uf's dev server and build are Vite — packages/vite/package.json depends on vite: "^8.2.2" and uf drives it over a JSON protocol. Bundling performance is not a row: it is the same bundler.

What uf adds. Flow's React syntax with no Babel anywhere in the pipeline; one config file instead of a vite.config.ts plus a test config plus a formatter config plus a linter config; and a test runner, formatter, linter and type checker that read the same syntax tree the build does.

What plain Vite keeps that uf gives up.

• TypeScript, and with it every typed package on npm.
• vite preview. uf has no equivalent; the driver implements one and nothing reaches it (#255).
• vite/client's types. import.meta.glob, import.meta.hot and asset imports are type errors or any under uf check (#264).
• Any Vite version you like. uf pins the line it tests against.

What does not change is the escape hatch: the vite key in uf.config.js is merged over what uf generates, and plugins is a list of ordinary Vite plugins.

Against Next.js

The largest gap, and the one worth being blunt about.

next build produces a running application: next start serves it, output: 'standalone' writes a self-contained server.js, and output: 'export' is the opt-in for the fully static case. In uf, the static case is the only case.

What uf has that Next.js does not. Flow's React syntax, checked by Flow's own inference. A formatter and a linter and a test runner in the same binary, reading the same tree — Next.js is a framework and expects you to bring those. And a framework that does not own a server, which is a feature exactly when you did not want one.

If you are building an application that renders per request, use Next.js. uf will tell you this again on What uf does not do rather than letting you find it out at deploy time.

Against Bun

Bun and uf overlap less than the feature lists suggest: Bun is a runtime that brings a package manager, a bundler and a test runner; uf is a toolchain that runs on a runtime — Bun included.

Where Bun wins, measured. bun test runs the same suite in 0.06 s against uf test's 0.20 s warm and 0.30 s cold, on 50 files, 1,000 tests and 2,000 assertions, best of five on an 8-core M-series Mac. That is about three times faster, and the reason is structural: Bun runs everything in one process with the runner written into the engine, while uf spawns a worker per core, gives each worker one file at a time, and pays the start-up. bun test also ships snapshots, coverage and a JUnit reporter; uf test has none of those (#280).

Where uf wins the same comparison. uf test is about nine times faster than vitest run on that suite (1.96 s), it runs on Node.js as well as Bun, and it runs Flow — bun test has no component or hook syntax at all.

Package management. uf does not implement one: uf install, uf add, uf remove, uf update and uf why each detect the project's package manager and run it, refusing a manifest that declares npm scripts and passing --ignore-scripts to whatever runs. uf install --frozen-lockfile is the CI install. Bun's installer is a finished product — a resolver, a global cache, a lockfile format, bun outdated, bun audit, bun patch, catalogs; uf's is a policy in front of yours, and deliberately: writing a resolver would make uf the chokepoint every ecosystem upgrade has to pass through.

And Vite+

Vite+ is the toolchain uf will be compared to most often, and it has its own page: uf and Vite+. The short version is that they answer different questions — Vite+ unifies the TypeScript toolchain, uf makes Flow's React syntax usable — and Vite+ has a company and a support contract, which uf does not.

So which one

• Writing TypeScript, shipping to production this quarter: Next.js if you need a server, Vite if you do not. uf is not competing for this.
• Writing TypeScript, unhappy about the number of config files: Vite+.
• Writing Flow, or wanting to: uf, and there is currently nothing else — which is the whole reason it exists.
• Building a static site, curious, willing to be early: uf builds this one. uf build prerenders every page of this documentation, and the output is what you are reading.

Where to go next

Migrating to uf is the honest cost of moving from any of the above. Flow and TypeScript is the language decision, which is the one that actually matters.

Next: uf and Vite+ →