The target option specifies which React version the compiler should generate code for.

{
  target: '19' // or '18', '17'
}

Reference

target

Configures the React version compatibility for the compiled output.

Type 

'17' | '18' | '19'

Default value

'19'

Valid values

  • '19': Target React 19 (default). No additional runtime required.
  • '18': Target React 18. Requires react-compiler-runtime package.
  • '17': Target React 17. Requires react-compiler-runtime package.

Caveats

  • Always use string values, not numbers (e.g., '17' not 17)
  • Don’t include patch versions (e.g., use '18' not '18.2.0')
  • React 19 includes built-in compiler runtime APIs
  • React 17 and 18 require installing react-compiler-runtime@latest

Usage

Targeting React 19 (default)

For React 19, no special configuration is needed:

{
  // defaults to target: '19'
}

The compiler will use React 19’s built-in runtime APIs:

// Compiled output uses React 19's native APIs
import { c as _c } from 'react/compiler-runtime';

Targeting React 17 or 18

For React 17 and React 18 projects, you need two steps:

  1. Install the runtime package:
npm install react-compiler-runtime@latest
  1. Configure the target:
// For React 18
{
  target: '18'
}

// For React 17
{
  target: '17'
}

The compiler will use the polyfill runtime for both versions:

// Compiled output uses the polyfill
import { c as _c } from 'react-compiler-runtime';

Troubleshooting

Runtime errors about missing compiler runtime

If you see errors like “Cannot find module ‘react/compiler-runtime’“:

  1. Check your React version:

    npm why react

  2. If using React 17 or 18, install the runtime:

    npm install react-compiler-runtime@latest

  3. Ensure your target matches your React version:

    {
      target: '18' // Must match your React major version
    }

Runtime package not working

Ensure the runtime package is:

  1. Installed in your project (not globally)
  2. Listed in your package.json dependencies
  3. The correct version (@latest tag)
  4. Not in devDependencies (it’s needed at runtime)

Checking compiled output

To verify the correct runtime is being used, note the different import (react/compiler-runtime for builtin, react-compiler-runtime standalone package for 17/18):

// For React 19 (built-in runtime)
import { c } from 'react/compiler-runtime'
//                      ^

// For React 17/18 (polyfill runtime)
import { c } from 'react-compiler-runtime'
//                      ^
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