ZIM (file format)

The ZIM file format is an open file format that stores website content for offline usage.

[1] The format is defined by the openZIM project, which also supports an open-source ZIM reader called Kiwix.

The format is primarily used to store the contents of Wikipedia and other Wikimedia projects, including articles, full-text search indices and auxiliary files.

[2][3] ZIM stands for "Zeno IMproved",[4][5] as it replaced the earlier Zeno file format.

Since 2021, the library defaults to Zstandard file compression[6] and also supports LZMA2, as implemented by the XZ Utils library.