Technologies come and go – never to be heard of again. CSS sprites, however, are a clear contradiction to this statement. After being widely used during the good old ‘8-bit gaming’ days, CSS sprites have bounced back in a new avatar, in the last few years – this time, as a useful tool for web developers to optimize the efficiency and loading speed of websites and other digital assets. In this post, we have tried to provide an overview of the various important aspects of CSS sprites, in a concise package.
Let’s get started!
CSS Sprites: An Introduction
Simply put, a CSS sprite is a collection of multiple two-dimensional images, aligned in a grid to form one large image, commonly referred to as a ‘sprite sheet’ or ‘tile set’. Although the practice seems fairly simple on the surface, it does have its share of intricacies. Including various manners of graphical overlays, contemporary CSS sprites are widely used in web development to integrate flat images into complex 3-D sections, which is done for a number of reasons, discussed ahead in the write-up.
Why use CSS Sprites?
Touted to be the contemporary alternative to old-school image slicing and dicing, CSS sprites are primarily used to enhance the page-load speed of a website. When a user visits a webpage containing multiple images, it generates multiple server requests, which in turn, slows down the loading speed. In contrast, as CSS sprites allow collating multiple images into one, employing the option reduces the number of server requests. In fact, it not only saves bandwidth, but also improves user experience.
How to Create CSS Sprites?
Although all the tools required for creating sprites are built into CSS (provided you know your way around), the process does require care and planning; however, it shouldn’t be a challenge for those who are familiar with the basics of using Cascading Style Sheets. Broadly classifying, there are four stages in the creation of CSS sprites – creating a master image, positioning it, creating a navigation menu, and finally, applying the CSS on navigation. Let’s take a closer look at each step.
Step 1: Create a Master Image
Before starting to create a master image, you must know the exact size of the images that are to be bundled in the sprite. If possible, it is advisable to use images of the same size and place them closely, as it will help with offset calculation.
All commendable CSS tricks strive to add a layer of visuals on a clean block of code, with sprints being no exception. Here, it is advisable to create a light-weight and simple markup that processes well in even in CSS-disabled browsers.
Image Source : https://css-tricks.com
Step 2: Position the Image
Accurately positioning the master image is extremely important to ensure visual finesse. Let’s say, we join two images of 50×50 pixels one over another. In this case, the master image will 100×50 pixels, with the respective images placed one over another. Use the master image as background in div tags. If you want the master image to show up somewhere on your page, you could create a CSS div class of ‘megaphone’. This is where you can define from where the image should be displayed.
Step 3: Create a Navigation and Apply the CSS
When it comes to creating a navigation menu, the way forward may vary with the type of sprite you create. Nonetheless, broadly, here is a how you go about it applying the CSS:
• Start with an HTML unordered list
• Convert the unordered list into a spite-based navigation
• Remove the default bullets by setting the list-style-type attribute to ‘none’
• Set all the common properties that the links will share, such as color, display, padding, etc.
• Define the default state of each of the links.
• Define the hover state of the links.
Tools to Create CSS Sprites
In case you are just getting started with CSS sprites, here is a list of some handy tools you can use:
In addition, you can also use Photoshop to work around with the contributing images and create master images for your CSS sprites.
CSS sprites are undoubtedly a remarkable tool in the arsenal of web design professionals who choose to use the option for a variety of reasons. In all cases, however, the main benefit of using CSS sprites is that they reduce the loading time of the webpage, thereby enhancing its performance as well as the visitors’ overall experience. In case you are having some difficulty in navigating your way through CSS sprites, simply speak with one of our representatives for a free consultation.