damian / use-fit-text

React hook used to fit text in a div

use-fit-text

React hook that iteratively adjusts the font size so that text will fit in a div.

• checks if text is overflowing by using scrollHeight and offsetHeight
• recalculates when container is resized (using (polyfilled) ResizeObserver)
• recalculates when content changes
• uses binary search; with default options, makes a maximum of 5 adjustments with a resolution of 5% font size from 20-100%
• < 4 kB minified + gzipped
• written in TypeScript

Installation

npm install --save use-fit-text

Usage

import React from "react";
import useFitText from "use-fit-text";

function Example() {
  const { fontSize, ref } = useFitText();

  return (
    <div ref={ref} style={{ fontSize, height: 40, width: 100 }}>
      Lorem ipsum dolor sit amet, consectetur adipiscing elit.
    </div>
  );
}

Options

• maxFontSize (default: 100) - maximum font size in percent
• minFontSize (default: 20) - minimum font size in percent
• onFinish (default: undefined) - function that is called when resizing finishes. The final fontSize is passed to the function as an argument.
• onStart (default: undefined) - function that is called when resizing starts
• resolution (default: 5) - font size resolution to adjust to in percent

Examples

See the example code in /examples.

Questions

• Why doesn't it work with Flexbox justify-content: flex-end;? This appears to be a bug with Flexbox. Try using CSS Grid or margin-top: auto;

Changelog

• v2.3.0
  • automatically recalculate font size when content changes
  • fix bug where a recalculation was not done on resize if the text initially fit in the div
• v2.2.0 - add onStart and onFinish callbacks
• v2.1.3 - export TOptions TypeScript type
• v2.1.2 - remove /// <reference types="next" /> in dist/index.d.ts
• v2.1.0
  • fix SSR/prerender issue where text did not resize
  • suppress useLayoutEffect warning for server render
• v2.0.0
  • use ResizeObserver to always recalculate on container resize
  • remove recalcOnResize option
  • useLayoutEffect instead of useEffect to avoid flashing
• v1.2.1 - fix scrollbar issue in example
• v1.2.0 - add recalcOnResize and other options
• v1.1.0 - fix binary search bug
• v1.0.2 - add example
• v1.0.0 - initial release