Publishers of technology books, eBooks, and videos for creative people

Home > Articles > Web Design & Development > CSS

What Are CSS Sprites?

If you're familiar with Web design concepts, you already know the basics of using Cascading Style Sheets (CSS). CSS sprites allow you to create a single file that contains all the images laid out in a grid, requiring only a single image and only a single server call. Jason Cranford Teague shows you how to tame your Web site graphics using CSS sprites to consolidate images into a single file.
Like this article? We recommend

The idea (and the last part of the name) for CSS sprites originates in the early days of video games, when memory and speed were at a premium. To overcome system limitations, video game producers would lay out the thousands of small graphics used to create a game into a grid and then display each "sprite" as needed, masking out all but the needed part of the larger image.

Using CSS sprites takes a little lateral thinking. Generally, we think about building a Web page similar to building with Legos: one block at a time. Sure, you can reuse the same image "block" several times throughout the same page (relying on that nifty caching feature to speed render time), but at the end of the load, each image is an island unto itself. There are several drawbacks, not the least of which is that every little image used in your interface, no matter how small, represents a server call that can slow down your Web page’s overall rendering.

CSS sprites allow you to create a single file that contains all the images laid out in a grid, meaning only a single image and only a single server call, with roughly the same file size because the empty space is compressed. In that file, you will place all individual "sprites" that make up your interface separated by enough space that they don’t start running over each other. You’ll then set the background position (using negative values to move the background up) and include enough space around each sprite so that only it appears in the background of the element, effectively masking the rest of the sprite images (see Figure 1).

Using CSS sprites takes some care and planning. You have to keep track of the pixel position of each sprite, but that’s not much harder than keeping track of the paths for the individual image files this single file will replace.

A Quick Example: Button Rollovers

CSS buttons have become a common technique in most Web developers’ arsenal of tricks. Where once we used clunky JavaScript to change the appearance of a graphic when the user rolls over or clicks it, modern Web designers use the CSS :link, :visited, :hover, and :active pseudo-classes to swap out images in the links background without ever having to program a single line of scripting code. However, there is a drawback in the form of a slight (but annoying) delay as the image files swap out. If we bang all of those images into a single sprite file, that problem goes away.

Creating the Background Image

First, we need to start by creating our four different image states, separated by enough space so that even if the links wrap some, we will not see the next button state poking up, as shown in Figure 2.

Here, I made the buttons a pretty good size and separated them by 100 pixels from the top of one button state to the top of the next state. This is important to remember because that means each button starts 100 pixels after the next, with a 10-pixel margin at the top so that they are a little better centered with the text of the link they will be placed next to. If you know the maximum width of a column, you can run your sprite images horizontally instead of vertically. Of course, whichever way you orient your sprites (vertically or horizontally), the extra space will add slightly to the file size, but if you save it as a GIF or PNG, the impact will be almost negligible.

One image element type that cannot be included in the sprite file is the tiled background. Obviously, if you need the image to repeat, you can’t have just a single area of the sprite image repeat.

Creating the Styles

Now it’s time for the code. To begin, let’s set up the links using a list:

<ul>
<li><a href="#a">Link A</a></li>
   <li><a href="#b">Link B</a></li>
   <li><a href="#c">Link C</a></li>
   <li><a href="#d">Link D</a></li>
</ul>

Nothing breathtakingly remarkable here. Without CSS, this list of links will look something like Figure 3.

Of course, we will be providing our own bullets, so we need to redefine the <li> tag to take out the default bullets:

li {
   font: 3em "Times New Roman", Times, serif;
   margin: 0px;
   padding:0px;
   height: 90px;
   overflow: hidden;
   list-style: none; }

Notice that I also set the height of list elements to 90 pixels (remember that there are 100 pixels between each button state) and hide any overflow. You will need to set the height to your specific needs, but this will ensure that the other button states stay masked when not needed. If you are designing with browsers other than Internet Explorer, you can set this as max-height, so that 90 pixels are not taking up the space unless needed.

Now it’s time for the links. We start with the generic link appearance when it is within a list tag:

li a {
    background: white url(images/buttons.png) 0px 0px no-repeat;
    padding-left: 40px; }

We are loading the image we saved (I called mine buttons.png and saved it in an image folder), have set its position to the top-left corner (0px 0px) meaning that the default state (link) is showing, and no repeating. We also need to set enough padding on the left side so that the text part of the link doesn’t overlap the image bullet in the background. This is, of course a matter of design. I’m using a pretty boring looking light bulb bullet for this example, but you may want to do something more exciting where the background image and text overlap and interact.

Now we need to define the background position for each state:

li a:link {
    color:#009900;
    background-position: 0px 0px; }
    li a:visited {
    color:#996666;
    background-position: 0px -100px; }
    li a:hover {
    color:#00cc00;
    background-position: 0px -200px; }
    li a:active {
    color:#cccc00;
    background-position: 0px -300px; }

For each state, we just move the background image up by 100 pixels. For each state, the background image slides up and down to show the relevant image for that state.

This rollover example is just a simple example of what you can do with CSS sprites. You can create much larger images used to provide not only interactive states but also with all the graphic chrome (except for backgrounds) contained within your site.

For more information on Web design, visit our Web Design Reference Guide or sign up for our Web Design Newsletter.

Peachpit Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Peachpit and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Peachpit products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email ask@peachpit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by Adobe Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.peachpit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020