When should you use useRef, and what is its essential difference from useState?

Short answer

useRef stores mutable values for the component's lifetime without causing a Re-render when they change, and also provides direct access to DOM nodes.

Explanation

A ref is an ordinary JavaScript object with a .current property. Changing ref.current does not notify React, so it does not cause a new render. It can store Timer IDs and previous state values, or control focus and media directly in DOM elements.

Code example

function TextInputWithFocusButton() {
  const inputEl = useRef<HTMLInputElement>(null);

  const onButtonClick = () => {
    // Direct access to the DOM element and focus the cursor
    inputEl.current?.focus();
  };

  return (
    <>
      <input ref={inputEl} type="text" />
      <button onClick={onButtonClick}>Focus the cursor</button>
    </>
  );
}

Common mistakes

• Reading or writing ref.current during Render instead of in event handlers or Effects.

Follow-up questions

• What is useImperativeHandle, and how do you use it with forwardRef to control a child component's interface?

Sources

• React docs — useRef