PHP QR Code

A pure-PHP QR Code 2D barcode generator. Generate QR codes from text, URLs, contact info, Wi‑Fi credentials, and more—with no external dependencies beyond the PHP GD extension.

Features

• Pure PHP — No external binaries or services
• AGPL-licensed — Free software; network use requires source disclosure (see LICENSE)
• Flexible output — PNG files, browser output, or raw matrix data for integration (e.g. TCPDF)
• Configurable — Error correction (L, M, Q, H), size, colors, cache options
• Web app & API — Includes a simple “qr.” web UI and a GET-based API for server-side generation

Requirements

• PHP 5.x or 7.x+
• PHP GD2 extension with PNG support (JPEG optional)

Installation

1. Clone or download this repository.
2. Ensure the cache directory (if used) is writable.
3. For the merged single-file build, use phpqrcode.php. For the modular build, use qrlib.php (which pulls in the rest).

Quick start (library)

<?php
require_once 'qrlib.php';

// Save to file: data, filename, ECC level (L|M|Q|H), pixel size per module, margin
QRcode::png('https://example.com', 'qrcode.png', 'L', 4, 2);

// Output directly to browser (must be first/only output)
QRcode::png('Hello, QR!');

Web interface

Open index.php in a browser. The “qr.” UI lets you enter URLs, text, email, phone, or Wi‑Fi details, choose colors and size, and download PNG/SVG (client-side generation uses a separate JS library; the PHP backend can be used for the API).

API

api.php provides a simple HTTP API:

Parameter	Description
data	Content to encode (required)
level	Error correction: L, M, Q, H (default: M)
size	Module size 1–10 (default: 5)
fg	Foreground color hex without # (default: 000000)
bg	Background color hex without # (default: ffffff)
dl	1 to send as download

Example:
/api.php?data=https%3A%2F%2Fexample.com&level=M&size=5&fg=000000&bg=ffffff

Returns a PNG image (or JSON error if data is missing).

Project structure

Path	Description
phpqrcode.php	Single merged file (no external includes)
qrlib.php	Main entry for modular build
qrtools.php	Utilities, cache, benchmark, TCPDF helper
api.php	HTTP API for PNG generation
index.php	“qr.” web UI
INSTALL	Extra configuration and TCPDF notes
LICENSE	GNU AGPL v3

Other files (qrconst.php, qrconfig.php, qrspec.php, etc.) are part of the library or the merged bundle.

Configuration

In the modular build, edit qrconfig.php (or the merged config section in phpqrcode.php): cache directory, logging, mask search behavior, and maximum PNG size. See comments there and in INSTALL.

TCPDF integration

See INSTALL and the bindings/tcpdf directory (if present) for wiring PHP QR Code into TCPDF’s 2D barcode support.

License and acknowledgments

• License: GNU Affero General Public License v3.0 (AGPL-3.0). If you use this code over a network (e.g. in a web API), you must offer the corresponding source under the AGPL.
• Original PHP QR Code: Copyright (C) 2010 Dominik Dzienia.
  Based on the C library libqrencode (LGPL) by Kentaro Fukuchi.
  Reed–Solomon encoder by Phil Karn, KA9Q.
• QR Code is a registered trademark of DENSO WAVE INCORPORATED.

Contributing

Contributions are welcome. Please read CONTRIBUTING.md and CODE_OF_CONDUCT.md before submitting changes.