URL-to-[QR,Code39,Data Matrix]

Simple, Fast Barcode Generation via URL

Introduction

Welcome to the documentation for URL-to-[QR,Code39,Data Matrix], a straightforward and efficient web service designed to generate QR codes, Code39, and Data Matrix barcodes dynamically. Simply construct a URL containing the text you wish to encode, and the service will return the corresponding barcode image.

This service is currently hosted at https://gen.printercow.com/. It leverages the power of Rust and high-quality libraries to deliver fast and reliable barcode generation.

Hosting & Performance: The service is currently hosted on servers located in Frankfurt, Germany. Users within Europe should typically experience very low latency, often sub-30ms for barcode generation requests.

We aim to provide the best possible performance globally. If you are experiencing high latency and would benefit from hosting in a different region, please let us know where you'd like to see servers deployed next! You can reach us at hello@printercow.com.

Usage

To generate a barcode, make a GET request to the appropriate endpoint at https://gen.printercow.com/. The text you want to encode should be appended to the URL path.

Important: The text included in the URL path ({text_to_encode}) must be URL-encoded if it contains special characters like spaces, slashes, question marks, etc. Most programming languages and tools have built-in functions for URL encoding (e.g., JavaScript's encodeURIComponent(), Python's urllib.parse.quote()).

QR Code Generation

GET https://gen.printercow.com/qr/svg/{text_to_encode} SVG

Generates a QR code in Scalable Vector Graphics (SVG) format.

Parameter: {text_to_encode} - The URL-encoded text to embed in the QR code (max 1000 characters).

Examples: 
# Using curl
curl "https://gen.printercow.com/qr/svg/https%3A%2F%2Fprintercow.com" -o printercow_qr.svg

# In HTML
QR Code for Hello World!
GET https://gen.printercow.com/qr/png/{text_to_encode} PNG

Generates a QR code in Portable Network Graphics (PNG) format.

Parameter: {text_to_encode} - The URL-encoded text to embed in the QR code (max 1000 characters).

Examples: 
# Using curl
curl "https://gen.printercow.com/qr/png/Check%20out%20Printercow%21" -o printercow_qr.png

# In HTML
QR Code for Simple Data

Code39 Barcode Generation

GET https://gen.printercow.com/code39/svg/{text_to_encode} SVG

Generates a Code39 barcode in Scalable Vector Graphics (SVG) format.

Parameter: {text_to_encode} - The URL-encoded text to encode. Max 1000 characters. Must only contain valid Code39 characters (see note below). Input text is automatically converted to uppercase.

Examples: 
# Using curl
curl "https://gen.printercow.com/code39/svg/CODE-39%20EXAMPLE%20123" -o code39_example.svg

# In HTML
Code39 for PART-NUMBER-456
GET https://gen.printercow.com/code39/png/{text_to_encode} PNG

Generates a Code39 barcode in Portable Network Graphics (PNG) format (default height: 80px).

Parameter: {text_to_encode} - The URL-encoded text to encode. Max 1000 characters. Must only contain valid Code39 characters (see note below). Input text is automatically converted to uppercase.

Examples: 
# Using curl
curl "https://gen.printercow.com/code39/png/ASSET%2F%24123.45" -o code39_asset.png

# In HTML
Code39 Barcode
Code39 Character Set: The standard Code39 specification supports uppercase letters (A-Z), digits (0-9), and the symbols: space, minus (-), plus (+), period (.), dollar sign ($), slash (/), and percent (%). This service enforces this limitation. Any provided text will be converted to uppercase. If invalid characters are detected, a 400 Bad Request error will be returned.

Data Matrix Generation

Data Matrix is a two-dimensional code consisting of black and white "cells" or modules arranged in either a square or rectangular pattern, also known as a matrix. It can encode text, numbers, and raw binary data, offering high density and error correction.

GET https://gen.printercow.com/datamatrix/svg/{text_to_encode} SVG

Generates a Data Matrix barcode in Scalable Vector Graphics (SVG) format. This format is ideal for high-resolution printing and scaling without quality loss. The generated SVG uses a rectangular symbol shape when appropriate for the data.

Parameter: {text_to_encode} - The URL-encoded text or data to embed in the Data Matrix code (max 1000 characters).

Examples: 
# Using curl
curl "https://gen.printercow.com/datamatrix/svg/PartID%3A%20SN123456789" -o datamatrix_part.svg

# In HTML
Data Matrix Code
GET https://gen.printercow.com/datamatrix/png/{text_to_encode} PNG

Generates a Data Matrix barcode in Portable Network Graphics (PNG) format. Suitable for web display and general use. The generated PNG uses a square symbol shape when appropriate for the data.

Parameter: {text_to_encode} - The URL-encoded text or data to embed in the Data Matrix code (max 1000 characters).

Examples: 
# Using curl
curl "https://gen.printercow.com/datamatrix/png/https%3A%2F%2Fprintercow.com%2Fdocs" -o datamatrix_url.png

# In HTML
Data Matrix Code

Error Handling

The service uses standard HTTP status codes to indicate success or failure:

  • 200 OK: The barcode was generated successfully. The response body contains the image data (SVG or PNG).
  • 400 Bad Request: This usually indicates an issue with the input text. Common causes include:
    • The {text_to_encode} path segment is missing or empty.
    • For Code39, the text contains characters not allowed in the Code39 character set.
  • 413 Payload Too Large: The provided {text_to_encode} exceeds the maximum allowed length (1000 characters).
  • 500 Internal Server Error: An unexpected error occurred on the server while generating the barcode. Please contact hello@printercow.com if you encounter persistent errors.

Error responses will typically include a plain text message in the body explaining the issue.

Limitations

  • Maximum Text Length: The input text for encoding is limited to 1000 characters. Requests exceeding this limit will receive a 413 Payload Too Large error.
  • Code39 Character Set: Only valid Code39 characters are supported (uppercase A-Z, 0-9, space, -, ., $, /, +, %).
  • Barcode Types: Currently, QR Code, Code39, and Data Matrix are supported. Let us know if you need support for other barcode types!

Usage Terms, Privacy & Contact

The URL-to-[QR,Code39,Data Matrix] service at https://gen.printercow.com/ is completely free to use for any purpose, whether personal or commercial, without any attribution requirements or limitations.

Privacy Commitment: We are committed to user privacy. No personally identifiable information or the content you encode is logged or stored. We do not log IP addresses, user agents, or the text/data you submit for barcode generation.

The only metric recorded is a simple, anonymous counter that increments each time a specific type of barcode (QR, Code39, Data Matrix) is generated. This counter helps us understand general usage patterns (e.g., "100 QR codes were generated today") without tracking any specific request or user.

For questions, feedback, bug reports, feature requests, or inquiries about hosting, please contact us at: hello@printercow.com.

Acknowledgements

This service relies on several high-quality open-source libraries. Special thanks to the maintainers of: