A DST file is a machine embroidery design — a list of instructions telling an embroidery machine where to put every stitch. The extension stands for the format's origin: it is the native format of Tajima industrial machines, and it has become the closest thing the embroidery world has to a universal file.
In this guide
What is actually inside a DST
Not a picture. This is the thing that surprises people most: there is no image anywhere in a DST file. The preview your machine or your software shows you is drawn from the stitch data itself, on the fly.
What the file holds is a header followed by a long run of three-byte records, one per stitch. Each record encodes a small relative movement — advance this far in x, this far in y — plus a flag saying what to do on arrival: put the needle down, travel with it up (a jump), cut the thread, or stop for a colour change.
That is the whole format. Three bytes per stitch is remarkably compact, which is why a design with 20,000 stitches is still only about 60KB.
The 512-byte header
Every DST opens with a fixed 512-byte block of plain text fields, each one a two-letter label followed by a value. The ones that matter:
| Field | Holds | Why you care |
|---|---|---|
LA: | The design name, up to 16 characters | What your machine displays in its file list — often not the filename |
ST: | Total stitch count | How long it will take, and whether it fits older machine memory |
CO: | Number of colour changes | How many times the machine will stop for you |
+X, -X, +Y, -Y | The design's extents from its start point | The real size — check it against your hoop |
Because those fields are up front and in plain text, software can tell you a DST's size and stitch count instantly without reading the stitches at all. That is what a DST viewer is reading when it reports the dimensions the moment you drop a file in.
The header being a fixed 512 bytes matters too: everything has to fit. A design with a great many colour changes can push the colour records past that boundary, and a writer that does not handle the overflow produces a file that is subtly corrupt rather than obviously broken.
Why DST has no thread colours
This is the single most common source of confusion about the format, and the answer is simple: the format has nowhere to put them.
A DST records "stop here for a colour change" and nothing whatsoever about what to change to. Not a name, not an RGB value, not a thread number. So when you open a DST and the colours look wrong, they are not wrong — they are invented, by whatever software you opened it in, because there was nothing to read. Open the same file in three programs and you will get three different palettes, all equally arbitrary.
Compare that with PES and JEF, which both store colours as an index into the machine manufacturer's thread chart. Those formats round your colours to a catalogue; DST does not round them, it discards them.
Why everyone asks for DST
Commercial embroiderers almost always request DST, and it is worth understanding why, because the reason is the same as the reason it loses your colours.
DST carries nothing brand-specific. No manufacturer's thread chart, no hoop metadata, no version field that a different machine might not recognise. That austerity is exactly what makes it portable — there is nothing in the file for an unfamiliar machine to choke on. Most brands read DST even though it is not their native format.
And for a commercial shop, losing the colours costs nothing: they are going to assign thread from their own stock regardless of what your file claims. What they want is the geometry, and DST carries that perfectly.
How to open a DST file
Your operating system will not preview a DST — it is not an image format, so there is nothing for Finder or Explorer to show you. Options:
- In a browser. The DST viewer reads the file on your own computer and plays it back stitch by stitch, showing the colour blocks, jumps, trims, stitch count and real dimensions. Nothing is uploaded.
- On the machine. Copy it to a USB stick and load it. Fine for stitching, poor for checking, because you find out about a size or memory problem at the machine.
- In digitizing software. Any of the desktop packages will open a DST, though most of them cost more than the design does.
Whichever you use, check the extents against your hoop before you commit fabric and stabiliser. That is a 20-second check that saves a ruined garment.
Converting to and from DST
Two different jobs get called "converting a DST", and it is worth separating them:
Changing format. You have a DST and your machine wants PES or JEF. Nothing is re-digitized here — the stitches are already decided and only the container changes, so it is a re-encode. The embroidery file converter does this. Going from DST, remember there are no colours to recover: the target file gets a palette the converter had to invent, so set it to what you actually intend before stitching.
Making a DST from artwork. You have a logo or image and need a DST. That is digitizing, and it is a genuinely different operation — shapes have to be turned into stitch paths, stitch types chosen, underlay generated. The image to DST converter does that.
Can you resize a DST?
A little. A DST is a fixed list of needle positions, so scaling it moves the positions further apart or closer together without changing how many there are. Scale up and the design goes sparse and gappy; scale down and the stitches pile into the same holes and the fabric turns to cardboard.
Roughly 0.8× to 1.25× is safe. Beyond that you are fighting the density, and past about half or double it stops being usable at all. For a real size change, go back to the original artwork and re-digitize at the size you want — which is also why keeping the source art matters more than keeping the DST.
Common questions
Is DST better quality than PES? No. The stitches are identical. DST is more portable and carries less metadata; that is the whole difference.
Why does my DST open with grey or random colours? Because it has no colours. Whatever you opened it in assigned some. Set them yourself before stitching.
Can a DST store a machine stop for appliqué? Yes. Stops are stitch flags, not colour data, so they survive fine.
My machine says the design is too large. Check the header extents in a viewer. If it genuinely exceeds your hoop, re-digitize smaller rather than scaling — see above.
What is the difference between DST and EXP? Both are stitches without a thread list, but EXP has no header at all, so it cannot tell you the design name, stitch count or extents the way a DST can.
Which should I use for my own machine? Whatever your manual names as native — DST only if that is a Tajima or industrial multi-needle. For choosing between formats generally, see PES vs DST vs JEF.