The Rust React Compiler cut a 1,036-file compile step from 14.3s to 0.81s

Put the two savings side by side and they do not fully reconcile. The compile step lost 13.49 seconds ^[1]. The whole build lost 12.8 ^[2]. So the non-compiler work in that pipeline went from 7.8 seconds to 8.49 across the two measurements ^[3]. Different runs, most likely.

Before the switch, compilation was about 65 percent of that build. After it, 8.7 percent ^[4]. The 0.81s pass is single-threaded ^[3], so there is time still available, and taking all of it would cut the build by under nine percent ^[4].

The 17.6x is a measurement of one workload, 1,036 files of a React Router app called Outlyne ^[2]. For the 2.4x whole-build figure to transfer, compilation has to be roughly two thirds of your build's wall time. Where it is a fifth, removing it completely caps the gain at 1.25x ^[5]. Boshen, the oxc project lead, gave a lower figure for the compiler alone: "It is more than 10 times faster than Babel in our preliminary benchmark," he said ^[7].

The post on blog.master.dev says its author is more interested in being on the latest version of the compiler than in the speedup ^[20]. Three patterns that made the Babel-based compiler bail now compile: conditional logic of any kind inside try/catch, which blocked many users of the stable 1.0 release ^[10]; reassigning a destructured component prop that is then used in a nested closure, support for which landed the week before he wrote ^[11]; and computed object property keys ^[12]. A throw from inside a try block and the logical assignment operators still cause the compiler to skip a component or hook ^[14].

The version skew is the practical part. He filed an issue against oxc after a component was neither optimized during the build nor flagged by Oxlint. Oxlint was using oxc-transform-react v0.145.0, which supports the pattern; he was testing against v0.144.0 of the same package ^[16]. One patch version between linter and build produced a bug report about a bug that did not exist. Both now run the same React Compiler with the same limitations ^[17].

Adoption cost is small if you are already current. @vitejs/plugin-react v6.1.0 calls the feature experimental native React Compiler support, and you turn it on by passing { compiler: true } to the plugin in your Vite config ^[5]. Switching an existing Vite build wants Vite v8 or newer ^[18]. React Router in framework mode does not go through that plugin, so the post uses @acusti/vite-plugin-react-compiler instead ^[6]. The stated motive is CI: agent-assisted development has raised build volume enough that GitHub Actions minutes are a cost center for the team ^[19]. On their own measurements, the switch returns 12.8 seconds a build ^[2].