SWC vs Babel: Which JS/TS Transpiler for CI?
SWC is a Rust transpiler that runs far faster than Babel; Babel has the mature plugin and preset ecosystem.
Babel is the long-standing JavaScript/TypeScript transpiler with a vast plugin and preset ecosystem. SWC (Rust) is a much faster drop-in for many Babel use cases and powers tools like Next.js and many test runners’ transforms.
| Babel | SWC | |
|---|---|---|
| Implementation | JavaScript | Rust |
| Speed | Slower | Much faster |
| Plugin ecosystem | Huge, mature | Smaller, growing |
| Presets / config | Extensive | Covers common needs |
| Used by | Many legacy/custom setups | Next.js, Vitest, others |
In CI
SWC slashes transpile time versus Babel, which speeds up builds and test transforms - often the difference is dramatic on large codebases. Many frameworks and test runners already use SWC under the hood. Babel remains necessary when you depend on specific plugins or custom transforms that have no SWC equivalent. A common move is to switch to SWC for speed and keep Babel only where a required plugin demands it.
Migration effort
Map your Babel presets/plugins to SWC config; most common cases (TypeScript, JSX, modern JS) are covered. Verify any custom or niche Babel plugins, since SWC’s plugin model differs. Caching transforms helps either way.
The verdict
Want much faster transpiling and your transforms are mainstream: SWC. Depend on specific or custom Babel plugins: keep Babel (or use both). SWC is the speed win when no niche plugin blocks it.