Decode diode color bands instantly with this free Diode Color Code Calculator. Identify diode types, part numbers, polarity bands, and markings for electronics repair, PCB troubleshooting, engineering, education, and manufacturing.
Silicon General Zener (Blue Band)
A single blue band under standard classification identifies the component as a Zener Diode.
1N4148 General Switching (JEDEC)
Decodes via standard JEDEC 5-band sequence. Represents high-speed silicon planar switching structures.
Germanium Varactor (AAX series)
Pro Electron standard: Band 1 (Germanium) + Band 2 (Varactor category) followed by numeric serial series identifiers.
Schottky Signal Diode (Green Band)
Uses a single green band indicator. Identifies low forward-voltage metal-semiconductor Schottky junction barrier diodes.
Axial leaded glass-body diodes (such as DO-35 or DO-41 form-factor casings) are extremely compact, making it difficult to print alphanumeric labels on their rounded surface. Manufacturers use color-coded bands to indicate part numbers.
These bands are usually offset closer to the **Cathode terminal (negative end)**. To decode, orient the diode so the thickest or most concentrated grouping of color lines is on the left, then read from left to right towards the cathode.
The cathode (negative terminal) is indicated by the color bands or terminal stripe. On leaded axial diodes, color bands are clustered closer to the cathode end.
Standard diodes conduct only in the forward direction. Zener diodes are designed to conduct reliably in the reverse direction once a specific 'breakdown voltage' is reached, making them useful for voltage regulation.
The '1N' prefix is part of the JEDEC standard, where '1' represents the number of active semiconductor junctions (diodes have 1 junction, transistors typically have 2, marked '2N').
Under general single-band coding standards, a single green band printed on the diode represents a Schottky classification.
Diode Color Code Calculator is a free online calculator tool. Use it to get instant, accurate results for your electronics calculations.