They're really different issues. Deduplication reduces the memory consumption of duplicate strings. Compact strings reduce the memory consumption of ascii strin

They're really different issues. Deduplication reduces the memory consumption of duplicate strings. Compact strings reduce the memory consumption of ascii strings, regardless of whether they're unique or mostly duplicates. So depending on your situation, you could want either, both, or neither. There is some overlap, however. If you have a lot of ascii strings but also a high level of duplication, either approach will save some memory, but if deduplication by itself saves x bytes, and compact strings saves y, using both will save a lot less than x + y bytes. And, like the later poster says, don't use String.intern() for deduplication.