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An anode refers to the more positive lead of a polarized component such as an LED. Components with anodes also have cathodes, the more negative lead.

Image of an LED from two perspectives showing anode and cathode. Also shown, the schematic symbol.

How to tell which lead is the anode and which is the cathode?!?#

Polarized components like LEDs and Electrolytic Capacitors are manufactured with different length leads so you can tell which lead is the anode and which the cathode.

Typically, the longer lead on a polarized component is the anode and the shorter lead is the cathode. Of course, that's if someone hasn't trimmed the leads.

To help avoid polarity confusion, manufacturers add other small details to components to help you determine if a lead is more positive or negative. For example:

  • Look closely at an LED from the top and you'll notice that one of the sides is flat, which indicates the side with the more negative lead.

  • Electrolytic Capacitors retain their cylindrical shape, and instead add a fancy painted stripe on their side to indicate their more negative lead.