Home > Articles > Web Development > HTML/CSS

  • Print
  • + Share This
This chapter is from the book

Writing Mobile Websites

In some ways, writing websites for mobile devices is a lot easier than it used to be. Although a lot more devices are out there, including smartphones and not-so-smart phones, tablets, internet TV devices, and even some picture frames, the devices are converging in what HTML5 features they support, and even in their sizes and shapes (to some extent).

When you’re creating a mobile website, the first thing to remember is that a mobile website is just a website. The best websites are built for every browser and operating system, or as many as possible.

However, you should still consider some basic questions when building a website that is intended for mobile devices:

  • What is the screen size and resolution of the mobile device?
  • What content do your mobile users need?
  • Is your HTML, CSS, and JavaScript valid and compact?
  • Should your site have a separate domain for mobile users?
  • What testing does your mobile site need?

What is the Screen Size and Resolution of the Mobile Device

When you’re working with mobile devices, obviously the screen size is going to be smaller than on a desktop. In general, with smartphones, you have to prepare for a few standard sizes:

  • 128 × 160 pixels—Phones such as the Fujitsu DoCoMo F504i
  • 176 × 220 pixels—Phones such as the HP iPAQ 510
  • 240 × 320 pixels—Smartphones such as Blackberry 8100 or the HTC Elf
  • 320 × 480 pixels—PDAs such as the Garmin-AsusA50 or the Palm Pre

Tablets add to the mix by having not only an increased screen size, but also having a variation in how they can be viewed. For example, most tablets (and some smartphones for that matter) can be viewed in portrait or landscape mode. This means that sometimes you might have a 1024-pixels-wide screen to work with, and other times 800 pixels wide or less.

However, in general, the tablets provide a lot more screen space for you to play with on mobile devices. You can assume you have around 1024–1280 pixels by 600–800 pixels for most tablet devices.

Browsing most websites in their standard format on an iPad is easy because the browser is as clear and easy to use as on a computer monitor. Plus, with the zooming capabilities on both iOs and Android, making small, harder-to-read areas bigger is easy.

What Content Do Your Mobile Users Need?

When you are designing a site for mobile devices, remember that users don’t always want to access the same content as someone browsing on a desktop.

For example, mobile customers are often, well, mobile. In other words, they may be in motion or away from their home or office and have a very specific need or desire when they visit your site. For example, when visiting a restaurant website on a mobile phone, a user riding in a car might need to quickly find the location of the restaurant and the phone number. If the mobile site doesn’t have the phone number and location front-and-center, the user might quickly give up on the site.

Content for mobile sites shouldn’t be limited, however. In fact, the W3C recommends “...making, as far as is reasonable, the same information and services available to users irrespective of the device they are using.”1

This doesn’t mean that you can’t change the format or location of your content, but getting to the same content on a mobile device as on a computer should be possible.

Is Your HTML, CSS, and JavaScript Valid and Compact?

You don’t have to worry about writing well-formed XHTML for mobile devices, but sticking to correct, standards-based HTML, CSS, and JavaScript ensures that your pages are visible by the largest number of devices. Plus, by validating your HTML, you will know it is correct.

Beyond writing valid HTML, you should consider avoiding a few things if you are writing web pages for mobile devices:

  • HTML tables—Avoiding tables as much as you can in mobile layouts is best because of the small size of the screen. Scrolling horizontally is difficult and makes the tables hard to read.
  • HTML tables for layout—You shouldn’t use HTML tables for layout of web pages in general, but on mobile devices they can make the pages load slower and look bad, especially if the table doesn’t fit in the browser window. Plus, when you use tables for layout, you almost always use nested tables, which make the pages load slower and are much more difficult for mobile devices to render.
  • Pop-up windows—Pop-up windows are often annoying in general, but on mobile devices they can make the site unusable. Some mobile browsers don’t support them and others open them in unexpected ways (often by closing the current window to open a new one).
  • Graphics for layout—Like using tables for layout, adding invisible graphics to add spaces and affect layout typically make many older mobile devices choke or display the page incorrectly. Plus, they add to the download time.
  • Frames and image maps—Many mobile devices don’t support these features in HTML. In fact, HTML5 no longer includes frames (other than the iframe) as a part of the specification because of the usability issues involved.

Also remember that mobile users often have to pay a fee for their bandwidth, so your web pages should be as small (in KB) as you can make them. The fewer HTML tags and CSS properties you use and server requests you make, the better browsing will be for mobile users.

Should Your Site Have a Separate Domain for Mobile Users?

Many websites have a separate subdomain for their mobile site. This makes finding the mobile site without having to bother with the regular domain easy for mobile users. These domains are typically something like m.example.com.

Having a separate mobile domain offers several advantages:

  • It makes your mobile site easier to find.
  • You can advertise the mobile URL separately from the normal URL, giving you more reach.
  • Having a separate mobile domain enables people on tablets or smartphones to switch to the full site just by switching domains.
  • Detecting mobile users and sending them to a separate domain is much easier than scripting changes to your CSS for mobile users.

When trying to decide how to handle your mobile site version, consider how you are going to maintain the site. You can create the mobile domain manually with completely separate pages, or you can use a content management system. Hour 4, “Detecting Mobile Devices and HTML5 Support,” covers this topic in more detail.

What Testing Does Your Mobile Site Need?

Be prepared to test your site on as many mobile devices as you possibly can. Although you can use your browser to test or emulate things such as screen size, you won’t see some of the horrible things that can go wrong if you don’t test on mobile devices directly, such as the following:

  • Packet size limitations by mobile carriers preventing your page or images from loading
  • Images loading incorrectly or not at all
  • Inability to scroll horizontally (which is nearly impossible to do on some phones)
  • Device-specific features not working that you were relying on
  • File formats not being supported

You likely don’t have an unlimited budget for buying mobile phones (and their associated cellphone plans), so what do you do? Here are some suggestions:

  • Use emulators—Both online and offline emulators are available for many different mobile devices. Most are free to use and they give you at least a start at testing your site for mobile devices.
  • Rent time on devices—Services exist that will allow you to rent time on multiple phones. You can justify the cost by getting a sense of how the phones handle your applications.
  • Buy some phones—This might seem like an expensive option, but if you are planning on doing a lot of mobile web development, it could be a reasonable investment.
  • Get help from friends and co-workers—This is one of the least expensive ways to test your site—simply ask to borrow phones or tablets from people you know. You just need to put your site on a live web server.

Ultimately, if you are going to do mobile development, you should have at least one mobile device you can test your pages on directly. The more devices you can test on, the better your sites will be.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT 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 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 information@informit.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 InformIT. 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.informit.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