How to Identify JST Connectors: A Comprehensive Guide

July 5, 2025 / Sam Tang

Table of Contents

Have you ever found yourself staring at a tiny connector, unsure if it’s the right one for your project? If you work with electronics, you’ve likely encountered JST connectors. These small yet essential components connect wires and boards in devices like 3D printers, drones, and rechargeable battery packs. However, with numerous series and similar-looking connectors from other manufacturers, identifying the correct JST connector can feel like solving a puzzle.

Don’t worry! In this detailed guide, we’ll walk you through the process of identifying JST connectors step by step, equipping you with the knowledge to ensure compatibility, safety, and success in your electronic projects. Whether you’re an engineer, a DIY enthusiast, or sourcing parts for a larger operation, this JST connector identification guide has you covered.

What Are JST Connectors?

Before diving into identification, let’s clarify what JST connectors are. JST stands for Japan Solderless Terminal, the name of a Japanese company (J.S.T. Mfg. Co., Ltd.) renowned for producing high-quality electrical connectors. Contrary to a common misconception, “JST” doesn’t refer to a single type of connector but to the manufacturer. JST offers a variety of connector series, each tailored to specific applications with distinct specifications.

Here’s a handy reference for popular JST connector types:

attributes \ series	JST SH	JST GH	JST ZH	JST PH	JST XH	JST SM	JST EH	JST RCY
LDZY series	A1001	A1257	A1500	A2001	A2501	C2505	A2502	C2510
pitch	1.0mm	1.25mm	1.5mm	2.0mm	2.5mm	2.5mm	2.5mm	2.5mm
circuit size	2 – 20	2 – 15	2 – 13	2 – 16	1 – 20	2 – 18	2 – 15	2
current rating	1A	1A	1A	2A	3A	3A	3A	3A
voltage rating	50V	50V	50V	100V	250V	250V	250V	250V
applicable wire (AWG)	32 – 28	30 – 26	32 – 26	32 – 24	30 – 22	28 – 22	32 – 22	28 – 22
configurations	wire to board	wire to board	wire to board	wire to board	wire to board	wire to wire	wire to board	wire to wire
single row	YES	YES	YES	YES	YES	YES	YES	YES
dual row	NO	NO	NO	NO	NO	YES	NO	NO
locking feature	NO	YES	NO	YES	YES	YES	YES	NO
through hole type	NO	NO	YES	YES	YES	/	YES	/
SMT type	YES	YES	YES	YES	YES	/	NO	/

How they look:

Here’s the catch: many connectors resemble JST products but come from other manufacturers. This similarity makes precise identification critical to avoid mix-ups.

Why Identifying JST Connectors Matters

Why bother with proper identification? The stakes are higher than you might think:

Compatibility: Using the wrong connector can result in a poor fit or an unreliable connection, leading to project failures or intermittent issues.
Safety: In power applications—think drone battery packs or RC vehicles—an incorrect connector could cause short circuits, overheating, or even fires.
Cost Savings: Misidentifying connectors can lead to costly procurement errors or assembly delays, especially in bulk production.

Taking a few minutes to identify the right JST connector can save you time, money, and headaches down the line.

Key Parameters for Identifying JST Connectors

To pinpoint the correct JST connector, focus on these four key parameters:

Type: Is it a wire-to-wire connector (linking two wires) or a wire-to-board connector (connecting a wire to a PCB)? For wire-to-board, note if it’s through-hole (pins go through the board) or surface-mount (pins solder to the surface).
Pitch: The distance (in millimeters) between the centers of adjacent pins. This is a defining trait, with common pitches like 1.0 mm, 1.25 mm, 2.0 mm, and 2.5 mm.
Number of Positions: The total count of pins or slots, typically ranging from 2 to 20.
Physical Characteristics: Look at size, shape, color, and unique features like locking mechanisms or latches. Color varies, but other traits can confirm the series.

Mastering these parameters is the foundation of successful identification.

Step-by-Step Guide: How to Identify JST Connectors

Ready to identify your JST connector? Follow this straightforward five-step process:

Step 1: Determine the Type

Wire-to-Wire: Does it connect two wires together? Think cables joining end-to-end.
Wire-to-Board: Does it link a wire to a circuit board? If so, check if the pins go through the board (through-hole) or sit on top (surface-mount).

Step 2: Measure the Pitch

Grab a digital caliper and measure the distance between the centers of two adjacent pins. Accuracy is vital—2.5 mm and 2.54 mm might seem close, but they indicate different connectors. Record your measurement in millimeters. (how to measure)

Step 3: Count the Number of Positions

Simply count the pins or slots. A 2-position connector has two pins, a 5-position has five, and so on. This narrows your options.

Step 4: Look for Markings or Labels

Examine the connector for molded or printed details—part numbers, series names (like “XH” or “RCY”), or the JST logo. These clues can instantly reveal the series.

Step 5: Compare with Known JST Series Listed Above

Use the table and pictures above to match your findings with common JST series. Cross-reference the type, pitch, and positions, and consider the connector’s typical use for confirmation.

Tips and Tricks for Accurate Identification

Avoid pitfalls and boost accuracy with these practical tips:

Steer Clear of Mistakes: Misjudging pitch is a common error—double-check your caliper readings. Also, don’t assume a connector is JST just because it looks familiar; verify with markings or specs.
Use Proper Tools: A digital caliper is a must for precise pitch measurement. For tiny markings, a magnifying glass can help.
Consult Official Datasheets: Found a part number or series name? Look it up in JST’s official datasheets to confirm details.

Conclusion

Identifying JST connectors doesn’t have to be a mystery. With this guide—determining the type, measuring the pitch, counting positions, checking markings, and comparing with known series—you can confidently select the right connector every time. Proper identification ensures your projects are compatible, safe, and efficient, whether you’re wiring a hobby project or sourcing parts for production.