FCKZPL API Documentation

A Labelary-compatible ZPL rendering API. Drop-in replacement for api.labelary.com.

Labelary-Compatible API

These endpoints follow the same URL pattern as the Labelary API, making FCKZPL a drop-in replacement.

curl -X POST https://fckzpl.com/v1/printers/8dpmm/labels/4x6/0/ \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "^XA^FO50,50^A0N,50,50^FDHello World^FS^XZ" \
  --output label.png

curl -X POST https://fckzpl.com/v1/printers/8dpmm/labels/4x6/0/ \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -H "Accept: application/pdf" \
  -d "^XA^FO50,50^A0N,50,50^FDHello World^FS^XZ" \
  --output label.pdf

curl "https://fckzpl.com/v1/printers/8dpmm/labels/4x6/0/?zpl=%5EXA%5EFO50%2C50%5EA0N%2C50%2C50%5EFDHello%5EFS%5EXZ" \
  --output label.png

<img src="https://fckzpl.com/v1/printers/8dpmm/labels/4x6/0/?zpl=^XA^FO50,50^A0N,50,50^FDHello^FS^XZ" />

Internal Render API

These endpoints power the FCKZPL web viewer and offer more configuration options than the Labelary-compatible API.

curl -X POST "https://fckzpl.com/api/render?width=4&height=6&unit=Inches&dpi=203&renderMode=Bicolor" \
  -H "Content-Type: text/plain" \
  -d "^XA^FO50,50^A0N,50,50^FDHello World^FS^XZ" \
  --output label.png

curl -X POST "https://fckzpl.com/api/render?width=4&height=6&dpi=203" \
  -F "zpl=^XA^CWA,R:MYFONT.TTF^FO50,50^AAN,40,40^FDCustom Font^FS^XZ" \
  -F "fonts=@MyFont.ttf" \
  --output label.png

curl -X POST "https://fckzpl.com/api/render/pdf?width=4&height=6&dpi=203&rotation=0" \
  -H "Content-Type: text/plain" \
  -d "^XA^FO50,50^A0N,50,50^FDHello World^FS^XZ" \
  --output label.pdf

Migration from Labelary

If your application currently calls the Labelary API like this:

curl -X POST http://api.labelary.com/v1/printers/8dpmm/labels/4x6/0/ \
  -d "^XA^FO50,50^A0N,50,50^FDHello^FS^XZ" \
  --output label.png

Just change the host:

curl -X POST https://fckzpl.com/v1/printers/8dpmm/labels/4x6/0/ \
  -d "^XA^FO50,50^A0N,50,50^FDHello^FS^XZ" \
  --output label.png

The URL pattern, request format, and response format are identical. Both application/x-www-form-urlencoded and text/plain content types are supported. PDF output via Accept: application/pdf header works the same way.

Limits 10 MB

The maximum request body size is 10 MB. This applies to all endpoints (ZPL text, font uploads, etc.).

If you need to render very large ZPL programs or upload many custom fonts, consider splitting them into separate requests.

Examples

Render a shipping label (PNG)

curl -X POST https://fckzpl.com/v1/printers/8dpmm/labels/4x6/0/ \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "^XA
^FO50,50^GB700,1100,3^FS
^FO50,50^A0N,60,60^FDShipping Label^FS
^FO50,150^BY3^BCN,100,Y,N,N^FD>:1234567890^FS
^FO50,300^A0N,40,40^FDJohn Doe^FS
^FO50,360^A0N,40,40^FD123 Main Street^FS
^FO50,420^A0N,40,40^FDNew York, NY 10001^FS
^XZ" \
  --output shipping-label.png

Get PDF output

curl -X POST https://fckzpl.com/v1/printers/12dpmm/labels/4x6/0/ \
  -H "Accept: application/pdf" \
  -d "^XA^FO50,50^A0N,50,50^FDHello PDF^FS^XZ" \
  --output label.pdf

Embed in an HTML page

<!-- Direct image embedding via GET -->
<img src="https://fckzpl.com/v1/printers/8dpmm/labels/4x6/0/?zpl=^XA^FO50,50^A0N,50,50^FDHello^FS^XZ" alt="Label" />

JavaScript fetch

const response = await fetch('/v1/printers/8dpmm/labels/4x6/0/', {
    method: 'POST',
    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
    body: '^XA^FO50,50^A0N,50,50^FDHello World^FS^XZ'
});
const blob = await response.blob();
const url = URL.createObjectURL(blob);
document.getElementById('label').src = url;

Python requests

import requests

zpl = "^XA^FO50,50^A0N,50,50^FDHello World^FS^XZ"
response = requests.post(
    "https://fckzpl.com/v1/printers/8dpmm/labels/4x6/0/",
    data=zpl,
    headers={"Content-Type": "application/x-www-form-urlencoded"}
)
with open("label.png", "wb") as f:
    f.write(response.content)

C# HttpClient

using var client = new HttpClient();
var zpl = "^XA^FO50,50^A0N,50,50^FDHello World^FS^XZ";
var content = new StringContent(zpl, System.Text.Encoding.UTF8, "application/x-www-form-urlencoded");
var response = await client.PostAsync("https://fckzpl.com/v1/printers/8dpmm/labels/4x6/0/", content);
var png = await response.Content.ReadAsByteArrayAsync();
File.WriteAllBytes("label.png", png);

// PDF output
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new("application/pdf"));
var pdfResponse = await client.PostAsync("https://fckzpl.com/v1/printers/8dpmm/labels/4x6/0/", content);
File.WriteAllBytes("label.pdf", await pdfResponse.Content.ReadAsByteArrayAsync());

Internal API with greyscale rendering

curl -X POST "https://fckzpl.com/api/render?width=100&height=60&unit=Mm&dpi=300&renderMode=Greyscale" \
  -H "Content-Type: text/plain" \
  -d "^XA^FO50,50^A0N,50,50^FDMetric Label^FS^XZ" \
  --output label-greyscale.png