Resistor Colors reads the markings on a resistor and tells you what it is — colour bands or SMD codes, and the other way round when you already know the value and need to find the part.
Built for makers, students, repair techs, and anyone who has ever squinted at four stripes under a desk lamp.
BANDS
Tap the colours you can see and read the value straight away. 3, 4, 5 and 6-band resistors are all supported, with tolerance and temperature coefficient where the part carries them, plus the real minimum and maximum the resistor is allowed to be.
The resistor drawn on screen matches the one in your hand, so you can check your reading against it band by band.
FIND
Know the value but not the colours? Type 4k7, 220, 0R22 or 1M and see exactly which bands to look for. The shorthand you already use is understood. If the value you asked for is not one that actually gets manufactured, the nearest one that is gets offered instead.
SMD
Decode the number printed on a surface-mount part: 3-digit, 4-digit, R notation, EIA-96, and zero-ohm jumpers. Some codes have more than one valid reading — 47R is both 47 Ω and 3.01 Ω — and every reading is shown rather than one being quietly picked for you.
SAVED
Keep the parts you look up most. Tap the bookmark on any result.
READ IT THE RIGHT WAY ROUND
A resistor has no top or bottom, and reading one from the wrong end is the easiest mistake there is. Every result is checked against the E6–E96 preferred-value series, and you are told when the answer is not a value anyone manufactures — which usually means the part is the other way round.
BUILT PROPERLY
• Works offline. Every calculation happens on your device.
• No account, no sign-in, nothing to set up.
• Exact decimal arithmetic, so 22 × 0.1 is 2.2 and not 2.2000002.
• Colour is never the only cue: every band is named in text, and every control is labelled for screen readers.
• Light, dark, or follow the system — plus six accent colours.
• English, العربية, Türkçe, Español and Français.
• Material 3 throughout, with an optional haptic tick on every tap.
Band colours always follow the IEC 60062 standard and never change with your theme.
Decode resistor colour bands, SMD codes and find the bands for any value