#193 · Frontend Framework Tools Developer Tool

React Checker

Check React JSX or TSX for syntax balance, Hook usage patterns, missing list keys, suspicious useEffect dependencies, import problems, and common accessibility issues.

Developer Input

React component, Hook, or snippet

React JSX or TSX source

import React, { useEffect } from "react";

export default function List({ items, query }) {
  useEffect(() => { console.log(query); }, []);
  return <ul>{items.map(item => <li>{item.name}</li>)}</ul>;
}

Checker mode

React version

version

Trim whitespace Preserve multiple empty lines Enable strict analysis Auto-run while typing

How to use this developer tool

Paste or enter the React source or specification.
Select the processing mode and configure the secondary option.
Run the tool and review the generated output, statistics, and practical notes.
Copy the result or download it for use in a project.

What this developer tool does

Check JSX or TSX for bracket balance, missing list keys, hook misuse patterns, useEffect dependency risks, imports, and accessibility warnings.

Normalize source → tokenize common React patterns → apply the selected transformation or analysis → calculate metrics → generate copy-ready output and recommendations.

The tool runs locally in the browser with deterministic JavaScript. It does not install dependencies, execute a React build, or replace TypeScript, ESLint, or framework tests.

Example

Use the included sample, run the tool, and compare the source with the generated report or transformed code. The sample is intentionally small enough to verify manually.

Tips for better output

Process one component at a time for the clearest line references.
Review generated code before committing it.
Use a project compiler and linter as the final authority.

FAQ

How do I use React Checker with JSX or TSX online?

Paste JSX or TSX, choose the relevant mode, and run React Checker. The result is generated entirely in the browser.

Does React Checker upload React source code to a server?

No. The included implementation processes the source in the current browser session.

Can React Checker process React 19 components?

Yes for the supported source patterns. Select or enter React 19 where available, then verify the result with your project toolchain.

Can I copy and download the React Checker result?

Yes. The output card provides copy and download controls after processing.

Does React Checker replace ESLint or TypeScript?

No. It provides a fast deterministic review or transformation, while ESLint, TypeScript, and build tests remain authoritative.

Related developer tools

React Generator React Formatter React Converter React Parser

Supported React analysis

Area	Support
Source	JSX and TSX patterns
Structure	components, Hooks, props, imports
Quality	syntax, accessibility, maintainability

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