zachleat’s Ugly Mug

Zach Leatherman

FitText + BigText: A Tale of Two Plugins

12 May 2011 Read in about 2 minutes #13 most popular

Earlier this week, @TrentWalton tweeted:

We at @paravelinc happily present to you FitText—a jQuery plugin for inflating web type:

Naturally, I wondered how it compared to BigText, a plugin of my own creation to Make Text Big. Trent continued:

It’s in the GitHub readme, but I want to recognize BigText from @zachleat as another font sizer for non-fluid sites:

I was delighted to get some attribution from Trent, and even more delighted to see their plugin. It’s really a great piece of work. However, his statement that BigText is just for non-fluid sites is not quite accurate. Let’s dive in.

On the surface, BigText and FitText might seem very similar. In fact, they are quite different and approach what might seem to be a similar problem (resizing text to fit a container) in very different ways.

At its simplest, we can boil it down like this: If you’re crafting a specific design with copy that is not going to change, use FitText. If your text is dynamic (maybe user generated), use BigText.

Here’s more detail:

DemosBigText FiddleFitText Fiddle
 Try resizing the demo windows above.
AlgorithmSizes text automatically from a base up to fit the element width, regardless of initial font size.Uses the width of the element and a configurable JavaScript argument (the ratio) to scale text down to smaller widths. This ratio argument must be set manually.
Responsive DesignBoth plugins work with responsive design techniques, operating correctly with media queries, fluid designs, and window resizing.
TextWorks with user generated text, or any text isn’t cemented at design time. See the BigText Demo Wizard.Requires up front configuration to specific text.
Resize EventWorks with existing debounced resize libraries, if they exist on the page.Does not use a debounced resize event.
UnobtrusiveCSS and BigText font-sizes are independent of each other.FitText uses your CSS font-size as a maximum font size.
 Don’t forget to set sane CSS font-size defaults when JavaScript isn’t available.
Unit TestedFull Test Suite-

FitText is very lightweight and fast, even considering it doesn’t yet use a debounced resize event. The FitText algorithm is quite beautiful. A huge well done to Paravel.

FitText relies on the fact that there is a linear relationship between font-sizes and element widths. Once you’ve established the ratio between the two, it’s off to the races. In fact, it would probably be technically possible to determine the ratio solely on the initial inner-width of the text and the initial font-size. I’ll have to play around with that approach but if it works it would give an amazing speed improvement to BigText.

font-size = outer-width / configurable-ratio

In a perfect world, BigText and FitText could be combined, to create a mutant auto-text-sizing plugin baby that gives the best of both worlds.