The first question is not which number to enter. It is which physical marking system is in front of you. A through-hole resistor with colored bands belongs to the Resistor Color Code Calculator. A chip resistor with a supported printed digit or letter code belongs to the SMD Resistor Code Decoder. A broader or uncertain SMD top marking that needs package context belongs to the SMD Component Marking Lookup. Choosing the matching route keeps the input contract and the result meaning aligned.
Use the through-hole color-band calculator for colored bands
Choose the through-hole route when the component is a traditional leaded resistor and the value is represented by colored bands. The band count, reading direction, significant digits, multiplier, and tolerance roles belong to that visual system. Do not enter an SMD printed mark such as 103 into the color-band workflow, because the same characters do not carry the same meaning as colored bands.
Use the SMD resistor decoder for printed resistor codes
Choose the SMD resistor route when the component is a chip resistor and the marking matches the supported printed code families. The current site decoder documents three-digit, four-digit, R-decimal, all-zero, and EIA-96-style workflows, with repository-confirmed examples such as 103, 1002, 4R7, 0, and 01C. Enter the literal printed marking, then verify the nominal result and the product series datasheet separately.
Use the SMD component marking lookup for broader top-mark context
Choose the component marking route when the question is about an SMD top mark together with package context rather than a confirmed resistor code. The current input contract includes a marking and a package selection. Its output is a candidate summary, so it is useful for narrowing a broader lookup, but it is not a confirmed model or complete specification. Keep the candidate tied to the package, manufacturer, board reference, and product series datasheet.
Compare the three routes
| Physical evidence | Correct route | Result boundary |
|---|---|---|
| Colored bands on a through-hole resistor | Through-hole color-band calculator | Color-band value interpretation |
| Printed SMD resistor code such as 103 or 4R7 | SMD resistor code decoder | Supported printed resistance code interpretation |
| Uncertain SMD top mark with package context | SMD component marking lookup | Candidate summary that needs context and documentation |
The route determines what the output means. A result from one system should not be copied into another system just because the visible characters look familiar.
Keep verification separate from decoder choice
After choosing the route, record the literal marking and the returned interpretation. For SMD resistor pages, the printed marking is only the starting evidence. Check tolerance, specification, package, and manufacturer details in the product series datasheet. For an ambiguous top mark, preserve candidates and use the package and board reference to narrow them. A route choice can organize the evidence, but it cannot establish a complete component selection on its own.
Source and limits
This page is a tool-selection guide for the three canonical decoder routes in the current site: through-hole color bands, printed SMD resistor codes, and SMD component markings with package context. It does not copy the detailed rules from those tools or turn any decoder result into a complete part specification.
- Use Resistor Color Code Calculator for through-hole colored bands.
- Use SMD Resistor Code Decoder for a supported printed SMD resistor marking, then verify the product series datasheet.
- Use SMD Component Marking Lookup for broader or ambiguous SMD top-mark context, and keep candidates unconfirmed until the documentation agrees.