[maxnevermind]

Parquet may consume less space because it uses encoding enhancements like delta encoding, run-length encoding, dictionary encoding. Also large number of tools that support Parquet as a format when Avro is Java and Hadoop centric.

[andrioni]

The other way around: Avro is supported by pretty much any language out there, while you can't even write a Parquet file on Python, and even reading it is pretty hard.