Author(s) leoetlino
Source code
License GPLv2+
Written in Python
Platform support Cross-platform

byml-v2 is an BYML tool. It can convert documents from BYML (or BYAML) to a human readable format (YAML) and vice versa. It is a newer tool that was written based on analysis of the official BYML code and game code in the executable. As such, this tool supports all the newer node types that are used in Breath of the Wild and other recent Switch games such as Super Mario Odyssey.


Install the byml package. [CLI help]


byml-v2 is a CLI tool. For help with using the command line, see Help:Using the command line.  

This tool automatically decompresses Yaz0-compressed files, and re-compresses them if the extension starts with an s. This means that you do not need to compress or decompress files manually.

  • To convert a BYML file to text (YML): byml_to_yml INPUT_FILE.byml OUTPUT_FILE.yml [help]
  • To convert back to binary YML: yml_to_byml INPUT_FILE.yml OUTPUT_FILE.sbyml [help] (add -b at the end for Wii U).

Known issues