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

Home > Articles > Gadgets and Digital Lifestyle

URL Shorteners: Handy but Risky

  • Print
  • + Share This
URL shorteners are handy for Twitter and IM, but they are not without security risks. Joel Postman explores the downside.
Like this article? We recommend

URL shorteners: handy but risky

Twitter, with its 140-character update window and lack of support for images, videos and files, has spawned an "ecosystem" of supporting sites and services. Highly popular among these are services like and that make lengthy URLs shorter.

URL shorteners are very handy for getting character counts down to fit into the small space of a Twitter update, IM, etc. They're also nice for creating URLs that don't "break" when emailed. (Large URLs often become corrupted when split from one line to another in email.)

Let's say you're heading off to school and you want to ask mom and dad for an HP Pavilion dv4t Special Edition netbook. Just copy the URL from into an email and send it to the folks:

Problem is, it's 165 characters. It will be unreadable in many email clients. And it's too long to tweet or DM on Twitter. The solution is to shorten it. There are dozens of URL shortening services available. Some merely make a shorter URL. Others, like or, add metrics (information on how often the URL has been clicked and other data), tools for managing URLs, and "vanity" URLs which can end in short English-language words instead of seemingly random strings like gh56he6.

As intriguing as it might seem, probably does not make your URL shorter. The shortest URLs I know of are generated by four-letter domain URL shorteners. I use, which creates 17-character URLs, if brevity is the primary goal. Otherwise, I use is the currently the most popular.

A not-so-short list of shorteners

If you're shopping for a URL shortener, there is a list of (ironically) 196 of them (so far) on the blog

Security risks of URL shorteners

There are many risks associated with URL shorteners that affect both business and personal users. Principal among these is that shortened URLs mask the source of the original link, so that they might point to content that is pornographic, violent, racist or other otherwise inappropriate. This is worrisome to both personal users who don't want to view this material and especially don't want their children to be exposed to it, and to business users who don't want employees viewing it and don't want their company associated with it.

This presents a challenge for businesses that choose to block inappropriate sites and content. Since shortened URLs mask the originating site, and most firewall software blocks by domain or IP address, corporate IT people are forced to either block all shortened URLs, or adopt solutions that decode URLs on the fly and test against a list of approved and banned domains. This is one more burden corporate IT departments don't need, and a problem services like Twitter need to respond to if they are to be taken seriously as business communications tools.

Jennifer Leggio, in a post on her ZDNet blog, quotes online security expert Dragos Ruiu:

"The negative part of this 'shortification' comes from the obscuring the visibility to the text of the URL before it gets sent to your browser -- it's a possible injection vector for direct browser URL exploits, of which there have been lots of varieties, and a way to send them to people without having the URL be inspected or visible. Or possibly just a way to send people to sketchy domains with worse hosted documents."

If the service you are using folds, or is unavailable due to IT outages, these shortened URLs will all be rendered useless on your blog, web site, Twitter/FriendFeed stream, etc. For this reason, most businesses are better off hosting their own shortened URLs in the form of "vanity" URLs, like, which are more secure, less prone to interruption of service, and more memorable to users. (It's often not possible to keep URLs this simple on shopping sites that use URLs to track complex transactional data, but other, more consumer- and communications-friendly approaches are needed.)

Yet another drawback of shortened URLs is the impact on Search Engine Optimization (SEO). Because shortened URLs mask the source site, analytics for that site may not factor traffic from these abbreviated URLs.

URL lengtheners

As I mentioned earlier, one solution to the problem of shortened URLs is to expand them before sending them to a browser. Services that do this, like have started to show up. There is an Untiny toolbar app, and Untiny's API lets developers include this capability in other programs and environments, so it's only a matter of time before this is built in to popular sites and services.

Responsibility of service providers

Service providers need to take an active role in preventing the use of shortened URLs to mask inappropriate content. Many sites take the attitude that they are merely tools, or a means by which people can communicate anything they'd like to, and that breaches are policed by "the community." More often than not this approach leads to a form of anarchy, unhappy users and migration to other sites. To maintain a safe environment for users, and one in which businesses can feel comfortable, site owners need to do more. Every URL shortener should have a Terms of Service (TOS) prohibiting these questionable uses, and defining penalties (deletion of URLs, banishment) for offenders.

This morning I was complaining on Twitter about the proliferation of spam followers and bogus URLs. I clicked on one TinyURL, and was pleased to see the company (one of the earliest URL shorteners) has a TOS and is enforcing it:

The company states in its brief Terms of Use "TinyURL was created as a free service to make posting long URLs easier, and may only be used for actual URLs. Using it for spamming or illegal purposes is forbidden and any such use will result in the TinyURL being disabled and you may be reported to all ISPs involved and to the proper governmental agencies."

So, if your business or personal use requires shortened URLs, factor the benefits and the risks of shortened URLs. And if someone emails you or tweets you a shortened link, as in all things connected with information, consider the source before clicking.

  • + Share This
  • 🔖 Save To Your Account

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.


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.


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.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email

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.


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


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


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 and we will process the deletion of a user's account.


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:

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

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.


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