[React] Auto resizing Textarea

Jay Kim
1 min readJun 19, 2023

Once I was given with the following acceptance criteria:

  • Do not show vertical scroll bar within the textarea
  • Height of the text area should only resize depending on the input value
  • Textarea has a minimum height

Implementation

import { useEffect, useRef, useState } from "react";
import "./styles.css";

export default function App() {
const textAreaRef = useRef<HTMLTextAreaElement | null>(null);
const [value, setValue] = useState(
"Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum"
);

const resizeTextArea = () => {
if (!textAreaRef.current) {
return;
}

textAreaRef.current.style.height = "auto"; // will not work without this!
textAreaRef.current.style.height = `${textAreaRef.current.scrollHeight}px`;
};

useEffect(() => {
resizeTextArea();
window.addEventListener("resize", resizeTextArea);
}, []);

return (
<div className="App">
<textarea
className="textarea"
value={value}
ref={textAreaRef}
onChange={(e) => {
setValue(e.target.value);
resizeTextArea();
}}
></textarea>
</div>
);
}
.textarea {
resize: none;
overflow: hidden;
width: 50%;
min-height: 10px;
background-color: #eee;
padding: 4px 8px;
}

Demo

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