ChargerLAB Power-Z KM003C Portable USB-C Fast Charging Tester PD3.2 QC5.0 Digital Voltmeter & Ammeter Power Bank Tester

The Chargerlab Power-Z KM003C is considered the best USB-C tester. It is the most expensive and is available on Amazon for $110. The new AlienTek C2 Pro is a very close second that is about half the price. AlienTek has been updating firmware and adding more capabilities like crazy lately. It is available for ~$50 on AliExpress. They both use the XHSC HC32F460JEUA ARM Cortex-M4 based microcontroller and high precision 20-bit ADCs. They are very similar in form and function, with E-Marker support and advanced charging protocol analysis. They both have very good PC software support. The KOWSI KWS-X1 is a ~$16 to $25 tester - much more limited than the KM003C and the C2 Pro even though it uses the same XHSC microcontroller. Its features are currently limited by its firmware. It has limited E-Marker simulation and protocol testing/triggering, including PD single trigger and PPS adjustment. That said, for ~$20 it provides a lot for its price.

Bare minimum is a continuity tester https://www.amazon.com/Treedix-Tester-Checker-Acrylic-Charging/dp/B0CF95VL2Y A step up is a continuity tester with resistance measurement https://www.amazon.com/dp/B07Y8BPVV4/ And in addition to that is a quality emarker reader https://www.amazon.com/ChargerLAB-KM003C-Portable-Charging-Voltmeter/dp/B0BJ24PVNJ You can find cheaper stuff, but this is what I use and recommend.