The JEF file format consists of files that are associated with the Janome NH10000 sewing machine. It contains embroidery and sewing patterns used on the machine. Most modern sewing machines come with software that allow you to download patterns in varying formats that work with different machine brands. If you need to convert to the JEF format for a Janome machine, you can do so using a free online file converter.
Navigate to https://www.embroiderydesigns.com/myconvertedfiles.aspx in your Web browser (note the "s" in "https").
Create a new account by entering a username, password and contact data.
Upload your PES file to the Embroidery Designs free conversion tool.
Click "Janome/JEF" as the output format.
Click "Convert Now."