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Resistor color code

Pick the bands and read the resistance: 4-, 5- or 6-band resistors, with significant-digit, multiplier, tolerance and (6-band) temperature-coefficient colors, showing the value, its ±tolerance range and the tempco in ppm/K. Or switch to reverse — type a resistance and a tolerance and get the color bands back, when the value fits the scheme's significant digits. A drawn resistor previews every band as you go. Runs entirely in your browser.

Privacy ledger

Data acquired None.
Libraries used Lit 3 — bundled into the tool file itself.
Data stored None.
Data transmitted None.

Use it on your own page

Download the tool as a single self-contained HTML file: readable source with the Lit library included, zero network requests — it works opened straight from your disk, and you can customize everything.

Prefer the hosted widget? One script tag embeds it and stays up to date:

<script type="module" src="https://uuutil.com/tools/resistor-color-code.js"></script>
<uu-resistor-color-code lang="en"></uu-resistor-color-code>

Source license: MIT — free to use, modify and redistribute; keep the license notice in copies.