want to generate SVG file of 2.5cm which contain 2600Bytes of data to SCAN in QR any suggestion

[lalwanikamaldev]

Type of issue

[ ] Question (e.g. about handling/usage)

Expected Behavior

Current Behavior

Possible Solution (optional)

Steps to Reproduce (for bugs)

Your Environment

[Shane32]

Versions (sizes) 38, 39, and 40 of QR codes support more than 2,600 bytes of content when using the low (L) ECC level. A "version 38" QR code has 169x169 modules. If you create a SVG, you can scale it to any size desired. However, for a 2.5cm QR code, each module would be approximately 0.15mm wide. It is quite unlikely that you could successfully scan such a large QR code printed so small with a typical handheld device. In fact, as this translates to 171dpi, it would be difficult to print/display this QR code accurately in the first place. But it is possible to do so.

Ref: https://www.qrcode.com/en/about/version.html

[Shane32]

Sample code:

using QRCoder;
using System;
using System.IO;

class Program
{
    static void Main()
    {
        // Example content with 2600 characters (this will need to be replaced by your actual content)
        string content = new string('a', 2600); // Replace this with your desired content

        // Initialize the QR code generator with low error correction level to accommodate a large amount of data
        QRCodeGenerator qrGenerator = new QRCodeGenerator();
        QRCodeData qrCode = qrGenerator.CreateQrCode(content, QRCodeGenerator.ECCLevel.L);

        // Generate the QR code as an SVG
        SvgQRCode svgQrCode = new SvgQRCode(qrCode);
        string svgString = svgQrCode.GetGraphic(1);

        // Save to a file or use the string as needed
        File.WriteAllText("qr_code.svg", svgString);

        Console.WriteLine("QR Code generated and saved as SVG.");
    }
}

[codebude]

As @Shane32 has already correctly pointed out: It is technically possible to encode ~2600 bytes in a QR code and save it as SVG. However, this becomes illegibly small with a display size of 2.5cm x 2.5cm.

I think here you will either have to distribute your user data over several codes or you store the data e.g. on a server and encode only the url to the data in a QR code.

I hope this answers your question. Let us know if there are any further questions or if we can close the issue.

[lalwanikamaldev]

Thank you @Shane32 for C# code sample , now i am able to generate the QR code but my reader is not able to read it . how can i build a reader which can read this small data ? As you mentioned it is too small to read .

@codebude i want qr contain all data offline .

[codebude]

A reader can read it if the image provided has enough details. I guess your reader uses a camera? In that case you must upgrade your hardware/camera to capture the image of the QR code with enough details. Every block must be clearly visibile in the image captured that you pass to your reader.