is london st pancras international the same as kings cross
No, they both are different stations.
St Pancras railway station
By the 1960s, St Pancras was surplus to requirements and services were diverted to King's Cross and but there was fierce opposition to its proposed closure and demolition of the station and hotel. 
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St Pancras railway station [SEP] Introduction
By the 1960s, St Pancras was surplus to requirements and services were diverted to King's Cross and but there was fierce opposition to its proposed closure and demolition of the station and hotel. In the late 20th century, it became the terminal for the Channel Tunnel Rail Link as part of an urban regeneration plan across East London. The complex underwent an £800 million refurbishment which was opened by Queen Elizabeth II in November 2007. A security-sealed terminal area was constructed for Eurostar services to mainland Europe via High Speed 1 and the Channel Tunnel, with platforms for domestic trains to the north and south-east of England.