Why are my Gradle APKs bigger than Ant's?

Question

I've been playing around with moving to Gradle, but realized our application size jumps up significantly by over 700kb for no real reason compared to our Ant build. I tried unzipping the APK files and rezipping them and they're more or less the same size.

Here is the ls output, of both APKs and the resulting re-zips.

-rw-r--r--   1 andrew  staff  7814614 May  8 16:09 ant-built.apk
-rw-r--r--   1 andrew  staff  7927650 May  8 16:12 ant-zipped.zip
-rw-r--r--   1 andrew  staff  8534075 May  8 16:10 gradle-built.apk
-rw-r--r--   1 andrew  staff  7963004 May  8 16:12 gradle-zipped.zip

As you can see the Gradle output is way bigger, but when zipped it's mostly the same size as the zipped version of the Ant build. Is there any reason the Gradle file would be bigger by default? Both APKs are zipaligned and signed. The zips were compressed using the basic zip command line. Not doing anything special in Ant or Gradle to make these builds.

Answer 1

It turns out we were doing an additional signing step in the ant build that was making the filesize smaller. Manually performing the two signing steps after an unsigned Gradle build creates equivalent sizes between Gradle and ant. Unfortunately I don't think it can be pinned down any further since it turns out I can't use Gradle's regular signingConfig for now.