Yes. The 1.0.0 release froze the wire format (almost, see below). All Zstandard releases after that are all interoperable. It’s funny though that you should as

Yes. The 1.0.0 release froze the wire format (almost, see below). All Zstandard releases after that are all interoperable. It’s funny though that you should ask that question now. Just yesterday I did submit an erratum on the RFC [0], changing a tiny detail of the spec. While it is literally, a breaking change, (1) we have not yet changed Zstd to produce outputs taking advantage of the change, and (2) it is not actually a concern, because all existing Zstd decoders ignore the existing spec in this regard. [0] https://www.rfc-editor.org/errata/eid5786 https://www.rfc-editor.org/errata/eid5786