How to Identify an Unknown Connector

The mystery connector — on a salvaged board, a prewired LED string, a drone part, a used printer — is the classic hobby problem. Here is the workflow that actually resolves it, instead of an hour of scrolling lookalike photos.

The workflow

1. Take clear photos from multiple angles — mating face, side (latch profile), wire entry, and next to a ruler. You'll reuse them for searching and for asking others.
2. Count positions. Total cavities, including unloaded ones.
3. Measure the pitch with calipers — center-to-center between adjacent contacts. Measure across the full row and divide, per Pitch: The Number That Saves You.
4. Determine the connection type:
   • wire-to-board — housing on wires, header on a PCB
   • wire-to-wire — two cable halves mate in-line
   • board-to-board — stacking/mezzanine, no wires
   • panel/feedthrough — mounted through an enclosure wall
5. Identify the latch/friction/keying — positive snap latch? friction only? polarizing bump or chamfer? Latch geometry separates lookalike families.
6. Identify whether the contacts are pins or sockets — look into the mating face.
7. Separate housing gender from contact gender. A "female" housing can hold pin contacts and vice versa — families define both independently, and listings confuse them constantly.
8. Measure housing dimensions — overall width/height/depth help discriminate between families with the same pitch.
9. Look for molded markings — manufacturer logos, series letters, or cavity numbers molded into the plastic are the fastest positive ID.
10. Search by pitch + positions + type + latch — not by what it looks like.
11. Compare manufacturer drawings, not just photos. Photos lie about scale; a dimensioned drawing either matches your calipers or it doesn't.
12. Buy test samples before committing to a bulk order or wiring a whole project.

Measure across multiple contact intervals and divide. The longer span reduces the effect of jaw placement and makes nearby pitch families easier to distinguish.

Search query examples

2 pin 2.0mm locking wire to board connector
3 pin JST-SM LED connector
4 pin 1.25mm JST GH cable
2.54mm dupont housing crimp terminal
JST PH 2 pin battery connector datasheet

Search results can be wrong

Marketplace listings routinely mislabel series, round pitches, and reuse stock photos of different connectors. Treat search results as candidates to verify against a manufacturer drawing — never as identification.

Related: the shared identification workflow (the short version both tracks use) · The Big Idea · Common Hobby Connector Families · the engineering track's How to Search for Connectors for the datasheet-driven version of this skill.