Meziantou.Framework.QRCode 2.0.4

Meziantou.Framework.QRCode

QR and barcode generation library with SVG and PNG renderers, plus a console renderer for QR codes. Implements QR code specifications from scratch with support for standard QR, Micro QR, and Rectangular Micro QR (rMQR) codes, and supports Code 39 / Code 128 linear barcodes.

Supported QR Code Types

Supported Barcode Types

Usage

The types are in the Meziantou.Framework namespace.

Generate QR codes (Standard, Micro QR, rMQR)

// Standard QR code
var standardQr = QRCode.Create("HELLO WORLD", ErrorCorrectionLevel.H);

// Micro QR code (smaller, single finder pattern)
var microQr = QRCode.CreateMicroQR("12345", ErrorCorrectionLevel.L);

// Rectangular Micro QR code (narrow rectangular shape)
var rmqr = QRCode.CreateRMQR("https://www.meziantou.net", ErrorCorrectionLevel.M);

// Format info: type, width and height in modules
Assert.Equal((QRCodeType.Standard, 25, 25), (standardQr.Type, standardQr.Width, standardQr.Height));
Assert.Equal((QRCodeType.MicroQR, 11, 11), (microQr.Type, microQr.Width, microQr.Height));
Assert.Equal((QRCodeType.RMQR, 43, 13), (rmqr.Type, rmqr.Width, rmqr.Height));

Generate barcodes (Code 39, Code 93, Code 128, EAN/UPC, Codabar, ITF)

var code39 = Barcode.CreateCode39("ABC-123", includeChecksum: true);
var code93 = Barcode.CreateCode93("ABC123");
var code128 = Barcode.CreateCode128("SKU-123456");
var ean8 = Barcode.CreateEan8("5512345");
var ean13 = Barcode.CreateEan13("400638133393");
var upcA = Barcode.CreateUpcA("03600029145", extension: "12");
var codabar = Barcode.CreateCodabar("40156", startCharacter: 'A', stopCharacter: 'B');
var itf = Barcode.CreateItf("12345678");

// Type, width in modules and height (a linear barcode is one module high)
Assert.Equal((BarcodeType.Code39, 129, 1), (code39.Type, code39.Width, code39.Height));
Assert.Equal((BarcodeType.Code93, 91, 1), (code93.Type, code93.Width, code93.Height));
Assert.Equal((BarcodeType.Code128, 123, 1), (code128.Type, code128.Width, code128.Height));
Assert.Equal((BarcodeType.Ean8, 67, 1), (ean8.Type, ean8.Width, ean8.Height));
Assert.Equal((BarcodeType.Ean13, 95, 1), (ean13.Type, ean13.Width, ean13.Height));
Assert.Equal((BarcodeType.UpcA, 122, 1), (upcA.Type, upcA.Width, upcA.Height));
Assert.Equal((BarcodeType.Codabar, 71, 1), (codabar.Type, codabar.Width, codabar.Height));
Assert.Equal((BarcodeType.Itf, 81, 1), (itf.Type, itf.Width, itf.Height));

Render as SVG

var qrCode = QRCode.Create("HELLO WORLD", ErrorCorrectionLevel.H);
var microQr = QRCode.CreateMicroQR("12345", ErrorCorrectionLevel.L);
var barcode = Barcode.CreateCode128("SKU-123456");

var svg = qrCode.ToSvg();
Assert.StartsWith("<svg xmlns=\"http://www.w3.org/2000/svg\" viewBox=\"0 0 330 330\">", svg);

var microSvg = microQr.ToSvg(new QRCodeSvgOptions { ModuleSize = 2, QuietZoneModules = 2 });
Assert.Contains("viewBox=\"0 0 30 30\"", microSvg);

var customSvg = qrCode.ToSvg(new QRCodeSvgOptions
{
    ModuleSize = 10,
    QuietZoneModules = 4,
    DarkColor = Color.FromRgb(0x00, 0x00, 0x00),
    LightColor = Color.FromRgb(0xff, 0xff, 0xff),
    LogoImageHref = "https://example.com/logo.svg", // Also supports data URIs
    LogoSizePercent = 20,
});
Assert.Contains("<image href=\"https://example.com/logo.svg\"", customSvg);

var barcodeSvg = barcode.ToSvg(new BarcodeSvgOptions
{
    ModuleWidth = 2,
    ModuleHeight = 80,
    QuietZoneModules = 10,
});
Assert.Contains("viewBox=\"0 0 286 80\"", barcodeSvg);

Logo images are currently supported in the SVG renderer only.

Render as PNG

var qrCode = QRCode.Create("HELLO WORLD", ErrorCorrectionLevel.H);
var microQr = QRCode.CreateMicroQR("12345", ErrorCorrectionLevel.L);
var barcode = Barcode.CreateCode39("ABC-123", includeChecksum: true);

// The content of a PNG file, to save with File.WriteAllBytes("qrcode.png", png)
var png = qrCode.ToPng();
Assert.Equal([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A], png[..8]); // the PNG signature

// Any writable stream, such as File.Create("micro-qrcode.png")
using var stream = new MemoryStream();
microQr.WriteToPng(stream, new QRCodePngOptions
{
    ModuleSize = 4,
    QuietZoneModules = 2,
    DarkColor = Color.FromRgb(0x1f, 0x29, 0x37),
    LightColor = Color.FromRgb(0xf9, 0xfa, 0xfb),
});

var barcodePng = barcode.ToPng(new BarcodePngOptions
{
    ModuleWidth = 2,
    ModuleHeight = 80,
    DarkColor = Color.FromRgb(0x0f, 0x76, 0x6e),
    LightColor = Color.FromRgb(0xec, 0xfe, 0xff),
});

Render to console

var qrCode = QRCode.Create("HELLO WORLD", ErrorCorrectionLevel.H);
var microQr = QRCode.CreateMicroQR("12345", ErrorCorrectionLevel.L);

qrCode.WriteToConsole();
var text = qrCode.ToConsoleString();

var microText = microQr.ToConsoleString(new QRCodeConsoleOptions
{
    QuietZoneModules = 1,
    ModuleWidth = 2,
    ModuleHeight = 2, // 2x bigger output that can look more square on many terminals
});

Assert.Equal("""

      ██████████████  ██  ██
      ██          ██
      ██  ██████  ██  ██████
      ██  ██████  ██
      ██  ██████  ██  ██████
      ██          ██    ████
      ██████████████  ██
                      ██████
      ████    ██████    ████
        ██  ██      ████
      ████████          ████

    """, microText, ignoreLineEndingDifferences: true);

Content helpers

// WiFi
var wifi = QRCodePayload.Wifi("MyNetwork", "password123", WifiAuthentication.WPA);
Assert.Equal("WIFI:T:WPA;S:MyNetwork;P:password123;;", wifi);

// vCard
var vcard = QRCodePayload.VCard("Doe", "John", phone: "+1234567890", email: "john@example.com");
Assert.StartsWith("BEGIN:VCARD\r\nVERSION:3.0\r\nN:Doe;John;;;\r\nFN:John Doe\r\n", vcard);

// MeCard (compact contact format)
var mecard = QRCodePayload.MeCard("Doe", "John", phone: "+1234567890");
Assert.Equal("MECARD:N:Doe,John;TEL:+1234567890;;", mecard);

// Email
var email = QRCodePayload.Email("test@example.com", subject: "Hello");
Assert.Equal("mailto:test@example.com?subject=Hello", email);

// Phone
var phone = QRCodePayload.Phone("+1234567890");
Assert.Equal("tel:+1234567890", phone);

// SMS
var sms = QRCodePayload.Sms("+1234567890", "Hello!");
Assert.Equal("smsto:+1234567890:Hello!", sms);

// Geolocation
var geo = QRCodePayload.Geolocation(48.8566, 2.3522);
Assert.Equal("geo:48.8566,2.3522", geo);

// Calendar event
var evt = QRCodePayload.CalendarEvent("Meeting",
    new DateTime(2025, 6, 15, 14, 0, 0, DateTimeKind.Utc),
    new DateTime(2025, 6, 15, 15, 0, 0, DateTimeKind.Utc),
    location: "Room 42");
Assert.Contains("DTSTART:20250615T140000Z\r\n", evt);

// OTP Auth (2FA setup)
var otp = QRCodePayload.OneTimePassword(OneTimePasswordType.Totp,
    "JBSWY3DPEHPK3PXP", "user@example.com", issuer: "MyApp");
Assert.Equal("otpauth://totp/MyApp:user%40example.com?secret=JBSWY3DPEHPK3PXP&issuer=MyApp", otp);

// Bitcoin payment
var btc = QRCodePayload.Bitcoin("1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa", amount: 0.05m);
Assert.Equal("bitcoin:1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa?amount=0.05", btc);

// SEPA payment (EPC QR)
var sepa = QRCodePayload.SepaPayment("Example", "DE00000000000000000000", 12.50m,
    remittanceText: "Donation");
Assert.StartsWith("BCD\n002\n1\nSCT\n", sepa);