Too many re-renders. React limits the number of renders to prevent an infinite loop. How to resolve the issue?

Infinite loops are the bane of every developer’s existence and React developers are not an exception to this rule. Luckily, React does a very nice job of detecting them and warning you about it before your entire device becomes unresponsive.

The “Too many re-renders” error in React occurs when there is an infinite loop of component re-renders. This often happens when a state update is triggered within the component’s rendering cycle, causing the component to re-render repeatedly.

Here are some common reasons for this error and how to resolve them:

1. State Update in Render: Check if you are updating the state directly within the render method. This can create an infinite loop. State updates should typically be done in response to events or lifecycle methods. Example of incorrect usage:

const MyComponent = () => {
  // Incorrect: Updating state directly in render
  useState(0); // Causes infinite re-renders

  return <div>Hello, World!</div>;
};

To fix this, move the state update logic to an event handler or a lifecycle method.

2. Incorrect Dependency Array in useEffect: If you are using the useEffect hook, ensure that the dependency array is correctly set. An empty dependency array ([]) means that the effect runs once after the initial render. If the dependency array is not set correctly, it can lead to repeated re-renders. Example of incorrect usage:

useEffect(() => {
  // Incorrect: No dependency array or incorrect dependencies
  setState(someValue); // Causes infinite re-renders
}, []);

To fix this, add the correct dependencies to the array or remove it if not needed.

3. State Update in an Event Handler: If you are updating the state within an event handler, ensure that the event handler is not causing a re-render loop. Example of incorrect usage:

const MyComponent = () => {
  const [count, setCount] = useState(0);

  const handleClick = () => {
    // Incorrect: Updating state in event handler without proper condition
    setCount(count + 1); // Causes infinite re-renders
  };

  return <button onClick={handleClick}>Click me</button>;
};

To fix this, make sure to use the setCount function with the current state value or utilize functional updates.

How to resolve this issue

As the warning suggests, the problem is that your component is triggering too many re-renders. This happens when your component queues too many state updates in a very short amount of time. The most common culprits for causing infinite loops are:

• Performing state updates directly in the render
• Not providing a proper callback to an event handler

If you’re running into this particular warning, make sure to check those two aspects of your component.

const Component = () => {
  const [count, setCount] = useState(0);

  setCount(count + 1); // State update in the render

  return (
    <div className="App">
      {/* onClick doesn't receive a proper callback */}
      <button onClick={setCount((prevCount) => prevCount + 1)}>
        Increment that counter
      </button>
    </div>
  );
}