Diode Color Markings

Identify diodes by their color bands and markings. Reference guide for MELF, axial, and glass package diodes.

About Diode Markings

Diodes come in various packages and are often marked with color bands or codes to indicate their type, voltage rating, or other characteristics. This guide will help you identify common diode markings and determine their specifications.

Hover or click on the diode images to see interactive information about each band.

Vishay Diodes

MELF or Axial Leaded Versions

General Purpose
MELF diode single black line
Black band indicates General Purpose diode
Schottky
MELF diode single green line
Green band indicates Schottky diode
Switching
MELF diode single yellow line
Yellow band indicates Switching diode
Zener
MELF diode single blue line
Blue band indicates Zener diode
Important Note

Vishay Diodes with these color bands only specify the type, not the voltage. If possible, you will have to do a breakdown check on a known good diode from the same circuit to identify the zener voltage.

Plastic MELF AND MiniMELF Markings

General Purpose
1st Band = Product Family
2nd Band = Peak Reverse Voltage

TYPE 1st BAND 2nd BAND
BYM10 series white gray: 50 V
red: 100 V
orange: 200 V
yellow: 400 V
green: 600 V
blue: 800 V
GL41 series white
BYM11 series red
RGL41 series red
BYM12 series green
EGL41 series green
BYM13 series orange gray: 20 V
orange: 40 V
green: 60 V
red: 30 V
yellow: 50 V
SGL41 series orange
TGL41-xx blue
ZGL41-xx red
BYM11/RGL41 800V
Plastic diode with bands red blue
Red band: BYM11/RGL41 series
Blue band: 800V rating
TYPE 1st BAND 2nd BAND
BYM07 series green gray: 50 V
red: 100 V
pink: 150 V
orange: 200 V
brown: 300 V
yellow: 400 V
green: 600 V
blue: 800 V
GL34 series white
EGL34 series green
RGL34 series red
RGL34 800V
Plastic diode with bands red blue
Red band: RGL34 series
Blue band: 800V rating

1NXXXX Series Diodes

Color Band Decoder

Colour 1st 2nd 3rd 4th Suffix
Black 0 0 0 0
Brown 1 1 1 1 A
Red 2 2 2 2 B
Orange 3 3 3 3 C
Yellow 4 4 4 4 D
Green 5 5 5 5 E
Blue 6 6 6 6 F
Violet 7 7 7 7 G
Grey 8 8 8 8 H
White 9 9 9 9 J
3-Band Example
Diode with 3 bands
Band 1: Blue (6)
Band 2: Yellow (4)
Band 3: Green (E)
Decoded Value:
1N64E
4-Band Example
Diode with 4 bands
Band 1: Yellow (4)
Band 2: Green (5)
Band 3: Red (2)
Band 4: Violet (G)
Decoded Value:
1N452G
5-Band Example
Diode with 5 bands
Band 1: Yellow (4)
Band 2: Violet (7)
Band 3: Yellow (4)
Band 4: Green (5)
Band 5: Brown (A)
Decoded Value:
1N4745A
How to Use

Using the above table to decode, you can identify the value of diodes with 3, 4, or 5 color bands. This applies to axial and MELF packages, as well as glass passivated versions. Hover over the bands in the examples above to see the color and value of each band.

Interactive Diode Decoder

Build Your Own Diode

Number of Bands:

Calculated Result

Diode Value
Diode Part Number: -
Band Readings

Related Tools

SMD Code Search

Identify surface mount components by their markings and find replacement parts.

Open Tool

Resistor Color Code

Decode resistor color bands and find resistance values with tolerance and temperature coefficients.

Open Tool

Capacitor Markings

Decode capacitor markings and calculate capacitance values for various package types.

Open Tool