If you decide to go with an electronic tuner, you should choose one with an LED display that will show you when the note being played is in tune. Most of these tuners will also show how far above or below perfect tune the particular string is, making adjusting the string accordingly a cinch. It is also a good idea to purchase a tuner that switches off automatically in order to save battery power.
An electronic ukelele tuner works by clipping onto the headstock of the uke and identifying the vibrational frequency of the note being played. It then displays this information to the user via a screen or LED lights. This information then allows the user to adjust the tightness of the string until the tuner shows that it is in tune.
With only four strings, tuning a ukelele is relatively easy compared with other instruments. However, you have the option of making things even easier by using one of the free online tuning applications available on the internet. Although these are generally free to use, you will need to have access to an internet connection. Additionally, it is important to keep in mind that these tuners are usually not as accurate as an electronic ukelele tuner since you are still relying upon your own sense of pitch to determine whether each string is in tune.
While an electronic ukelele tuner is not free like an online tuner, it has the advantage of being small and lightweight enough to take with you wherever you go. Furthermore, clip-on uke tuners are available for every budget. Even the inexpensive models work very well, and by paying a bit more, you can get access to some extra features that make tuning even easier and more convenient.
Since each person has different taste, you will also want to consider the design and appearance of a ukelele tuner before purchasing. For example, you may prefer a colorful chromatic display that allows you to easily view the display in low-light environments, or you may be partial to a rotating display that allows for multiple viewing angles.
Since the purpose for obtaining a ukelele tuner is to keep your ukelele sounding the way it is supposed to, it's important to choose a tuner that is both easy to use and that you enjoy using. Making this small investment will allow you to ensure that your ukelele consistently sounds great when playing for yourself and others.