textFit - Hassle-Free Text Fitting

A fast, dependency-free text sizing component that quickly fits single and multi-line text to the width and/or height of its container.

Example

Capabilities

textFit is:

• Fast, using binary search to quickly fit text to its container in log n time, making it far faster than most solutions.
  • Most fits are <1ms. See the implementation details.
• Dependency-free.
• Small. 4.1KB minified and 1.5KB gzipped.
• Supports both horizontal and vertical centering, including vertical centering with Flexbox for maximum accuracy.
• Supports any font face, padding, and multiline text.

Browser Support

textFit supports IE9+, Firefox, Chrome, Opera, and most mobile browsers. If you find an incompatibility, please file an issue.

If you require IE <= 8 support, please use the jQuery version. Functionality is identical between v1.0 and v2.0, the only change was the removal of the jQuery dependency.

Changelog

v2.4.0

• Added stopOverflow. If there is too much text then the text will still overflow outside of the div at the smallest font size. Setting stopOverflow to true will add a .overflow class to the seleted div if the text is overflowing. It also adds CSS which hides the text that is overflowing in order to keep the design of the page.
• Added maxLines. Similar to stopOverflow but instead it adds the class if there is too many lines of text. This setting takes an input of false or a number of lines to apply the limit at. This needs to be improved but it's still useful to have now.
• Added fontUnit. Changes the unit used in the minFontSize and maxFontSize. This allows units such as cm, mm, in, pt, pc, em, vw, vh, % and rem to be used instead of px.
• Added fontChangeSize. This changes the amount of the font is changed by when trying to find the final font size. The default is 1 but changing this to a decimal is sometimes needed. When using rem or em font units 0.1 or 0.01 is a recommended change size.

v2.3.1

• Fix #20 - properly iterate over HTMLCollection objects.

v2.3.0

• Added alignVertWithFlexbox. This does better vertical alignment and fixes #14.

v2.2.0

• Throw errors instead of just printing to console when missing height/width.
  • Removed options.suppressErrors. Wrap in try/catch instead if you really need this.
• Slight refactor.
• Added automatic build on prepublish.

v2.1.1

• Fixed a bug with alignVert when reprocessing.
• Added full UMD shim and published to npm.

v2.1

• Reworked alignVert.
• reProcess is now true by default. Set to false if you want to fire-and-forget on potentially processed nodes. This was originally false by default because it was being used in an infinite scrolling list.

v2.0

• Removed jQuery dependency.

Usage

<div class="box" style="width:300px;height:300px">
  Fit me, I am some text
</div>

// textFit accepts arrays
textFit(document.getElementsByClassName('box'));
// or single DOM elements
textFit(document.getElementsByClassName('box')[0]);
// Use jQuery selectors if you like.
textFit($('#box')[0])

The text will scale until it reaches the horizontal or vertical bounds of the box. Explicit width and height styles are required in order to fit the text.

Advanced Usage

Multiline Strings

If your text has multiple lines, textFit() will automatically detect that and disable white-space: no-wrap! No changes are necessary.

<div class="box" style="width:300px;height:300px">
  This text <br>
  Has multiple lines <br>
  Fit me!
</div>

textFit(document.getElementsByClassName('box'))

If, for some reason, the automatic detection is not working out for you, use the following to explicitly turn on multiLine fitting:

textFit(document.getElementsByClassName('box'), {multiLine: true})

Horizontal/Vertical Centering

<div class="box" style="width:300px;height:300px">
  This text <br>
  Has multiple lines <br>
  And wants to be centered horizontally and vertically<br>
  Fit me!
</div>

textFit(document.getElementsByClassName('box'), {alignHoriz: true, alignVert: true})

Minimum and Maximum Sizes

Sometimes you want to make sure that your text remains sanely sizes if it is very short or very long. textFit has you covered:

<div class="box" style="width:300px;height:300px">
  Short Text
</div>

textFit(document.getElementsByClassName('box'), {minFontSize:10, maxFontSize: 50})

Implementation Details

textFit determines reasonable minimum and maximum bounds for your text. The defaults are listed below.

To ensure accurate results with various font-faces, line-heights, and letter-spacings, textFit resizes the text until it fits the box as accurately as possible. Unlike many similar plugins, textFit uses binary search to find the correct fit, which speeds the process significantly. textFit is fast enough to use in production websites.

textFit() is a synchronous function. Because of this, resizes should be invisible as the render thread does not have a chance to do a layout until completion. Normal processing times should be < 1ms and should not significantly block renders.

Default Settings

From the source, for reference:

settings = {
    alignVert: false, // if true, textFit will align vertically using css tables
    alignHoriz: false, // if true, textFit will set text-align: center
    multiLine: false, // if true, textFit will not set white-space: no-wrap
    detectMultiLine: true, // disable to turn off automatic multi-line sensing
    stopOverflow: false, // if true, a error we be thrown if the content is overflowing
    fontUnit: 'px', // what unit should the final font be. using rems or mm is sometimes useful
    fontChangeSize: 1, // how much should the font size by ajusted by each time. 0.1 and 0.01 is useful for when using a rem font unit
    minFontSize: 6,
    maxFontSize: 80,
    reProcess: true, // if true, textFit will re-process already-fit nodes. Set to 'false' for better performance
    widthOnly: false, // if true, textFit will fit text to element width, regardless of text height
    alignVertWithFlexbox: false, // if true, textFit will use flexbox for vertical alignment
};

License

MIT