Resistor colour decoder

Decode four- or five-band resistor values and tolerance. Free, simple, and right here in your browser.

Preparing your tool…
A little possibility, waiting.Your result will appear here.
A useful little guide

How to use resistor colour decoder

Decode four- or five-band resistor values and tolerance. This browser tool shows the inputs, assumptions and resulting output so you can use it for a specific everyday task.

  1. Enter your own values or choose a supported file.
  2. Adjust the options and run the tool.
  3. Review the result, then copy, export or save it when available.
A real use case

Try this next

Decode brown, black, red and gold as a four-band resistor.

A detail to keep in mind

Read band direction and verify parts with a meter when needed. The decoder does not identify damaged or nonstandard components from a photo.

Questions, answered.

Is resistor colour decoder free to use?

Yes. This tool is part of Nepocore’s free browser toolkit. There is no paid tier, file-download gate or application account required.

What should I check before using the result?

Read band direction and verify parts with a meter when needed. The decoder does not identify damaged or nonstandard components from a photo.

Does this tool upload my files or text?

The tool processes its input in your browser. File contents and text are not sent to a processing server. See the privacy page for local storage and hosting details.

A little more in your toolkit

See the category