No software is perfect. Between the project blindness that developers can get after working on the same project for a long time and the fact that users are particularly good at using software in ways it wasn’t intended, even a program that appears to work flawlessly at first glance may be hiding a ticking time bomb. Having professional software test engineers evaluate your software before release is incredibly important. These four types of common software bugs happen often, and represent only some of the issues that can be found by an experienced software testing team.

Input Fields Malfunctioning

How many values can your users put into an input field? Unless you’ve provided pre-built options, an unlimited number. Sometimes those values won’t even be what the field is asking for—such as accidentally typing a phone number into the Zip Code field. With many types of input, there are also several variations that can represent the same basic value (e.g. filling a country field with U.S.A., U.S., USA, United States, etc.)

Your programming will not be able to differentiate between value categories, or recognize multiple variations representing the same value, unless you tell it to. This is a huge cause of input field malfunctions and often leads to bugs caused by accepting an incompatible value when it should present an error, or rejecting a legitimate value it doesn’t recognize. While this might not seem like a huge problem to start, later on it can cause massive confusion when other parts of your programming try to process those incompatible values.

Browser Incompatibility

Browser compatibility errors are about more than just aesthetics. When your software is incompatible with a certain browser, it can make the interface and even the commands beneath the browser malfunction in a way that makes your software unusable to the user.

Browser incompatibility errors are especially likely when the user is using an older or rarer browser, such as Internet Explorer, Opera or an older version of Safari. Mobile browser incompatibility is also no longer an option for websites and other web-based software, so your software needs to be tested for compatibility with those browsers as well.

Unfriendly U/X

Again, user interface problems are about more than just the way the program looks to the user. Bad user design bugs occur when a problem exists between what a user reasonably expects the program to do based on the interface, and what the program actually does. For example, if the user clicks a button that reads “save,” they expect the program to save their content and not delete it or submit it as incomplete.

Not all users intuit programs at the same level, nor do they need the same type of interface aspects. For example, a user that’s visually impaired will not pick up visual cues and will have to rely on your software working well with their screen reader, or still being navigable when the text size is increased. Your software developers may not have considered the rarer user interface issues such as this, so you should always have your software professionally tested.

Boundary Condition Issues

Boundary condition issues occur when a software is unable to properly process data above or below a certain value. These common software bugs have caused financial trading programs to lose hundreds of thousands of dollars, chemotherapy equipment to give patients unintentional radiation poisoning, and are the reason everyone in 1999 was afraid computers would stop working on New Years Day, 2000. They absolutely should not be underestimated.

These bugs are incredibly common and even the smallest example can wreak big havoc on your software under the right circumstances. But, with quality software testing, they can all be found before that happens. Make sure you protect your software and the investment of time and money it represents by getting your programs properly tested before launch.