Visible fraying or exposed wire
Replace immediately — this is both a charging-reliability issue and, in rarer cases, a genuine safety concern.
Charging becomes inconsistent
If you\’re wiggling the cable to get it to charge, that\’s internal wire damage, not a phone problem, and it will only get worse.
Noticeably slower charging over time
Cables degrade gradually with bending and daily use; a cable that used to fast-charge and no longer does is a sign of internal wear, not necessarily your charger or phone.
How to extend a cable\’s life
Avoid sharp bends right at the connector, don\’t wrap it tightly around a charger for storage, and unplug by the connector, not by pulling the cable itself.