Once the HTTP client parses the headers, the InputStream will be returned to "Retrofit", which will then pass it directly to Converter . This means that since the main conversion mechanism (say Gson) pulls bytes, they are read (and potentially blocked) directly from the network.
Note: this is only true if logging is disabled (as it should be in production / release assemblies). When logging is enabled outside of the HEADERS level, the response body must be fully read in byte[] in order to both log and transmit data to the converter.
source share