What a JEF file contains
The JEF header holds the date, the hoop code (e.g. RE20b, SQ14b), the number of colours, indices into the 78-thread Janome palette and the stitch count. Then 2-byte records per stitch (x, y move in tenths of a millimetre), with codes for jumps, colour changes and end. A trim is encoded as three zero-length jumps. The machine compares the header hoop to the mounted hoop and refuses a design made for a larger one.
Which machines read JEF
Every Janome embroidery machine (Memory Craft 230E to 15000, Skyline, Continental, MB-4 and MB-7) and Elna eXpressive. See Janome.
Opening a JEF file
Drop it above or open the viewer: the design appears in relief with colours, stitch count, size and estimated run time. A whole folder opens as thumbnails. The file is read in your browser and sent nowhere.
Producing a JEF file
From an image: convert an image to JEF. From another file: PES to JEF, DST to JEF. Broderly writes the hoop chosen in the Hoop panel and matches your threads to the Janome palette.
Technical details
- Extension .jef; binary header with offset to stitches, date, hoop code, colour and stitch counts, colour list and changes.
- Signed 2-byte stitches; jumps, colour changes and end through 0x80 escape sequences.
- 78-thread Janome palette; off-palette threads are matched to the nearest.
Frequently asked questions
“Design too large for the hoop” although it fits
The hoop written in the file is larger than the mounted one. Pick exactly the mounted hoop in the studio and re-export.
Can I open a JEF on Brother?
No, convert it to PES with the studio.
Go further
The studio is free to draw, open and check designs. Your first machine file takes five minutes.
Updated 2026-09-24.