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Glossary / USB-C

Active vs. passive cable

Why some USB-C cables carry high speeds over longer lengths.


A passive USB-C cable is plain wiring plus an e-marker; a longer active cable adds signal-conditioning chips (retimers) so it can carry high data rates over greater distances. Thunderbolt and USB4 beyond short passive lengths require active cables. Cablyst reads the e-marker to show what a given cable actually supports rather than what its length implies.

See it on your own cable — install Cablyst, check a cable, or browse the full glossary.

Related: E-marker  USB Power Delivery (USB-PD)  Extended Power Range (EPR, 240 W)  Thunderbolt 4  Thunderbolt 5  USB4  DisplayPort Alt Mode  VDO (Vendor Defined Object)  USB-IF (USB Implementers Forum)  PDO (Power Delivery Object)  SOP' (cable plug identity)  UHBR (Ultra High Bit Rate)