ZPL (Zebra Programming Language) is the standard way of telling a
thermal label printer "print this, here". You do not send an image file; you send
text, and the printer does the drawing.
The skeleton of a ZPL label
Every label starts with ^XA and ends with ^XZ.
Everything in between belongs to that label. The smallest meaningful label looks
like this:
^FO50,50 — Field Origin: the top-left corner of the
field. The unit is dots, not millimetres; how large a dot is
depends on the printer's resolution.
^A0N,40,40 — font and size. N is the orientation
(normal); R, I and B rotate by 90, 180 and
270 degrees.
^FD — Field Data: the actual content to print.
^FS — Field Separator: closes the field. Forget it and
the following commands are treated as a continuation of the same field, which
makes the label look nothing like you expected.
Dots, dpmm and label size
Coordinates in ZPL are dots, and the physical size of a dot depends on the
printer's density. The common values are 8 dpmm (203 dpi) and
12 dpmm (300 dpi). The same ZPL that looks right on an 8 dpmm
printer comes out small on a 12 dpmm one, because the same number of dots covers
fewer millimetres. This is the most common "it worked on my machine" problem in
ZPL.
^PW sets the label width and ^LL its length. If you
set neither, the printer falls back to its own defaults and your output varies
from machine to machine.
The three most common mistakes
A missing ^FS. The field never closes, so the
following commands write into it — you get a label with "half of it gone".
A field outside the label bounds. When an ^FO
coordinate exceeds ^PW/^LL, the content is silently
clipped: the printer reports no error, it simply does not print it.
Wrong barcode parameters. Every symbology accepts a
different character set and length; giving EAN-13 twelve digits, or Code 39 a
lowercase letter, produces a barcode that will not scan.
The six commands you will use first — and where each is explained
You do not learn ZPL by reading the whole programming guide. Six commands
cover the skeleton above; each has a reference page with syntax, an example
and what our renderer does with it.
From here the usual path is: keep the
ZPL cheat sheet open while writing, look
up anything else in the command reference, and
when a file lands on your desk, read
how to open a ZPL file and
how to send ZPL to a
network printer. The dot-versus-millimetre question above has its own
walkthrough with measured numbers in
dots, mm, inches and
DPI migration. ZPL is Zebra's language; TSC printers speak TSPL and Zebra
mobile printers CPCL — the ZPL hub lists the tools, the
printers that run it and the comparisons with the other languages.
Seeing it before you print it
The hard part of ZPL is that seeing the result normally requires a physical
printer and a roll of labels: one attempt equals one label. Labelixa's preview
draws the ZPL at its real size in the browser and points out structural problems
— overflowing fields, a missing ^FS — with the line number. No
printer required.
Frequently asked questions
Is ZPL the same on every Zebra printer?
The language is shared, but the output depends on the printer's dot density: positions are given in dots, so the same ZPL prints at different physical sizes on a 203 dpi and a 300 dpi printer.
Do I need a printer to learn ZPL?
No. An online viewer or a rendering API draws the label from the code, so you can read, write and fix ZPL before any printer is involved.
What do ^XA and ^XZ mean?
They open and close one label. Everything between them describes that label; commands outside the frame are ignored, which is one of the most common beginner mistakes.
Is ZPL a format or a language?
A language. ZPL describes a label as commands the printer executes, so the same file can print at different physical sizes on different printers — a fixed format like PNG could not do that.
Which ZPL commands should I learn first?
Six cover most labels: ^XA/^XZ to frame the label, ^FO for position, ^A for font and size, ^FD with ^FS for the data, ^PW/^LL for the label size and ^BC for a Code 128 barcode. Everything else is a variation on these.
