Animate element to auto height with jQuery

The detailed breakdown

Set up the stage for animation

First off, if you plan to animate from a settled height to 'auto', it's essential to determine the final destination for the element's height:

1. Record the existing height.
2. Alter the height to 'auto' for the moment.
3. Capture the scrollHeight.
4. Revert the height, and then:

var $div = $("#yourElement"); // Replace this with the ID of your div, obviously :P

// Here comes the magic saving
var originalHeight = $div.height();

// Hey, you're not supposed to be this tall!
$div.css('height', 'auto');

// Whoops, that's your natural height
var autoHeight = $div.height(); 

// My bad, let's shrink you back
$div.height(originalHeight); 

// Finally, let's give you some animation steroids!
$div.animate({ height: autoHeight }, 500, function() {
  $(this).css('height', 'auto'); 
});
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Balancing chains and heights

Chainability is crucial for a fluent Interface to queue more actions after the animation completes. Consider storing originalHeight and autoHeight using .data() for effortless retrieval and future use.

Bring in the CSS

Combining jQuery with CSS can lead to a more the merrier situation. Utilize the power of CSS transitions to enhance jQuery animations:

#yourElement {
  transition: height 0.5s; /* Smooth ride in 0.5 seconds */
  height: 0; /* Humble beginnings */
  overflow: hidden; /* Keep the extras at bay until showtime */
}
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var $div = $("#yourElement");
// All aboard the transition express!
$div.css('height', $div.get(0).scrollHeight + 'px');

$div.on('transitionend', function() {
  // Curtain call - switch to 'auto'
  $(this).css('height', 'auto');
});


Flip between classes to toggle between a fixed height and 'auto', taking advantage of the CSS transition magic.

Welcoming jQuery plugins

A custom solution gives you control, but why do more when you can do less? jQuery plugins, like slideToggle or slideDown, simplify the animation process and help maintain a clean codebase.

Pitfalls, tips, and tricks

Dealing with dynamic content

If your content can change dynamically (like an AJAX call can do), recalculating the autoHeight becomes crucial to ensure the transition accuracy remains top-notch.

Keeping performance in check

Animation performance is crucial – directly animating the height property can result in reflows. Minimize DOM manipulation and use min-height instead of height to stay performant.

Ironing out browser discrepancies

Different browsers may handle scrollHeight differently, particularly with paddings and borders. It's wise to ensure consistency, so test across all targeted browsers.