AppEngine gzip compressing

The App Engine frontend servers rely on a number of factors, including the Accept-Encoding and User-Agent headers to determine if they should compress responses. They do this because there are a number of user agents out there that claim to accept gzipped responses, but actually can't understand them.

Try setting your user agent to something sensible (and not 'gzip', which isn't a real user agent), and see if that makes any difference.