A higher-wattage USB-C PD adapter is generally safe when standards-compliant because the Mac negotiates the power it accepts.
Use About This Mac or the serial-linked specification to find the year and size. Visual similarity does not establish charger generation.
Original MagSafe, MagSafe 2 and MagSafe 3 use different connectors. The MagSafe-to-MagSafe 2 converter does not make those adapters compatible with MagSafe 3.
USB-C charging requires a PD adapter and cable able to negotiate the needed profile. The cable can limit power even when the brick rating is high enough.
Only supported Mac models fast charge, and Apple specifies particular adapter and cable pairings. Ordinary charging can work at lower wattage without reaching the fast-charge rate.
System Information shows the wattage reported by the connected AC charger. A Slow Charger message indicates the current solution does not meet the preferred power level.
A lower-wattage source can charge slowly or fall behind during heavy use.
