To make sure that your instrument performs in tune, and that you are in tune with the band, a tuner pedal remains an essential tool for any electric or acoustic guitarist or bass player. Although today there is a huge range of tuners available as clip-on headstock style or handheld, there are many choices and form factors available for pedal tuners as well.
In the past, the only choice of a pedal tuner was monophonic, tuning one string at a time. For many players this is perfectally fine, and practical. Some of these tuners have very small form sizes so if your pedal board is quite busy, you could always find a small pedal tuner to fit on the board. Now, there is a choice of polyphonic tuners available, which allows you to tune all strings at once. Some tuner pedals offer all-analogue buffered bypass, and true bypass features, which is useful for boosting a signal along long cable runs or large pedalboards. Some tuner pedals even act as a power supply for other pedals.