Fixing 'Cannot Be Used as a JSX Component' in React

Fixing 'Cannot Be Used as a JSX Component' in React

If you're working with React and TypeScript, you might encounter the following error:

'ComponentName' cannot be used as a JSX component.
Its instance type is not a valid JSX element.

This issue is common after upgrading dependencies or when there's a mismatch between react, react-dom, and @types/react versions. Here’s how to fix it.

Why Does This Error Occur?

The error is typically caused by:

1. Mismatch Between React and Type Definitions – Using react@17 with @types/react@18 or vice versa.
2. React 18 JSX Type Changes – React 18 changed how JSX elements are handled.
3. Third-Party Dependencies – Some libraries might use an outdated version of @types/react.
4. Issues with tsconfig.json – Incorrect TypeScript configuration can cause type issues.

How to Fix 'Cannot Be Used as a JSX Component'

1. Check Installed Versions

Run the following command to check your installed versions:

npm list react react-dom @types/react @types/react-dom

Ensure they match the correct versions:

• If you're using React 17, you should have @types/react@17.
• If you're using React 18, you should have @types/react@18.

2. Update React and Type Definitions

If your versions are mismatched, update them accordingly:

For React 18:

npm install react@18 react-dom@18 @types/react@18 @types/react-dom@18

For React 17:

npm install react@17 react-dom@17 @types/react@17 @types/react-dom@17

3. Modify tsconfig.json (For TypeScript Projects)

Ensure your tsconfig.json file has the correct settings:

{
  "compilerOptions": {
    "jsx": "react-jsx",
    "paths": {
      "react": ["./node_modules/@types/react"]
    }
  }
}

4. Delete node_modules and Reinstall Packages

Sometimes, the error is caused by cached dependencies. Clear them and reinstall:

rm -rf node_modules package-lock.json
npm install

For Yarn users:

yarn install --check-files

5. Fix Issues with Third-Party Libraries

If you're using a third-party package like react-icons, react-redux, or @mui/material, check for compatibility issues.

For example, in react-icons, incorrect imports can cause this issue:

// ❌ Wrong Import
import { IconName } from 'react-icons/fa'

// ✅ Correct Import
import { FaIconName } from 'react-icons/fa'

6. Change How React is Imported

If you're using TypeScript, try changing your import statement:

// ❌ Might cause issues
import React from 'react'

// ✅ Fix by importing everything as React
import * as React from 'react'

FAQs

1. Why does this error happen after upgrading React?

React 18 introduced changes in JSX handling. If your type definitions don’t match your React version, TypeScript throws this error.

2. How do I check my TypeScript version?

Run the following command:

tsc -v

If you're using an outdated version, upgrade it:

npm install -g typescript

3. Will downgrading React solve the issue?

It might, but it's better to ensure all dependencies match instead of downgrading.

4. Do I need to modify my components?

Not necessarily. The issue is typically related to dependencies rather than your component code.