Baseline.js

Baseline.js is a simple jQuery / Zepto plugin for restoring baselines thrown off by odd image sizes.

Simply call the plugin like so, passing the height of your baseline as a variable. It even works on responsive designs!

$('img').baseline(24); // Apply a 24px baseline to all images on the page
$('.content img').baseline(30); // Apply a 30px baseline to all images inside .content

You can also define multiple baselines for different breakpoints. Perfect for responsive design!

$('.content img').baseline({ '0px': 24, '700px': 30 }); // Apply a 24px baseline for all widths, 30px for widths above 700px

Or you can pass a function that must return a number which is used as the grid size.

$('.content img').baseline(function() {
  // Get the current font-size from the HTML tag – the root font-size `rem` –
  // which may change through to some CSS media queries
  return parseFloat(getComputedStyle(document.documentElement, null).getPropertyValue('font-size'));
});

The used CSS may look like:

html   { font-size: 12px; }
@media (min-width: 480px) {
  html { font-size: 13px; }
}
@media (min-width: 720px) {
  html { font-size: 14px; }
}
@media (min-width: 1024px) {
  html { font-size: 15px; }
}

body {
  /* This one is a computed value based on the given root em
   * and is used as the final font-size for body copy. */
  font-size: 1.2rem;
}

Vanilla JS

Baseline.js is also available without jQuery or Zepto.

baseline('img', 24); // Apply a 24px baseline to all images on the page
baseline('.content img', 30); // Apply a 30px baseline to all images inside .content
baseline('.content img', {0:24, 700:30}); // Apply a 24px baseline for all widths, 30px for widths above 700px

The first parameter accepts either a selector string or one or more elements, e.g. selected through document.getElementById().

The vanilla JS version was initially created by the rocking Ben Howdle.

License

Baseline.js is licensed under the WTFPL license.