Building a Custom QR Generator Tool with Python in Less Than 5 Minutes

Why a tiny QR generator script is worth five minutes

QR codes are a simple way to share URLs, dashboards or docs without typing long links. In this tutorial you will build a tiny Python script that turns any string into a QR code image and adds a centre logo in a single function call.

Step 1: Install the QR code dependencies

We will use the qrcode library to generate the QR matrix and Pillow (PIL) to handle images and the logo overlay.

pip install "qrcode[pil]" Pillow
    

Make sure you are using a recent Python 3 environment (for example in a virtualenv) so this script stays isolated from your system packages.

Step 2: Create a minimal qrtool.py

Next, create a file called qrtool.py and paste in this minimal script. It focuses only on generating a QR code and placing a logo at the centre, without any extra styling.

#!/usr/bin/env python3
"""
Minimal QR generator with optional centre logo.
"""

from pathlib import Path

import qrcode
from PIL import Image


def make_qr_with_logo(data: str, logo_path: str | None, out_path: str = "qr.png") -> None:
    # Use high error correction so the QR stays readable after adding a logo
    qr = qrcode.QRCode(
        version=None,
        error_correction=qrcode.constants.ERROR_CORRECT_H,
        box_size=10,
        border=4,
    )
    qr.add_data(data)
    qr.make(fit=True)

    # Base QR image
    img = qr.make_image(fill_color="black", back_color="white").convert("RGBA")

    if logo_path:
        logo_file = Path(logo_path)
        if not logo_file.is_file():
            raise FileNotFoundError(f"Logo not found: {logo_file}")

        logo = Image.open(logo_file).convert("RGBA")

        # Keep logo around ~25% of QR width so it does not dominate the code
        qr_w, qr_h = img.size
        logo_size = int(qr_w * 0.25)
        logo.thumbnail((logo_size, logo_size), Image.LANCZOS)

        logo_w, logo_h = logo.size
        pos = ((qr_w - logo_w) // 2, (qr_h - logo_h) // 2)

        # Paste logo in the centre using alpha channel
        img.alpha_composite(logo, dest=pos)

    img.save(out_path)
    print(f"Saved QR code to {out_path}")


if __name__ == "__main__":
    # Simple example: change these values or wire up argparse if you prefer
    make_qr_with_logo(
        data="https://plexdata.online",
        logo_path="plex_logo.png",
        out_path="qr.png",
    )
    

This keeps everything in one place: the QR code generation, safe error correction settings and a small logo overlay function that you can reuse in any project.

Step 3: Add a centre logo safely

When you put a logo in the middle of a QR code you cover some of the data modules. To keep the code scannable, the script does two things for you:

• Uses ERROR_CORRECT_H so the QR can tolerate more damage or obstruction.
• Resizes the logo to roughly a quarter of the QR width so it stays visually strong without overwhelming the pattern.

All you need to supply is a square-ish logo file (for example plex_logo.png) in the same folder as the script.

Step 4: Generate your own QR code

With qrtool.py saved and your logo file in place, you can generate a QR code in a single command:

python qrtool.py
    

Update the data, logo_path and out_path values in the if __name__ == "__main__" block to point at your own URL, logo file and output filename. You now have a reusable, minimal QR generator script you can drop into any project.

Skip the build: use the PLEX repo or web tool

If you would rather not type out the script yourself, you can clone the full version used in PLEX articles and demos:

Related PLEX reading

References & further reading

• PyPI — qrcode
  Official documentation for the Python qrcode library used to build the QR matrix.
• GeeksforGeeks — Generate QR Codes with a custom logo using Python
  Example of combining qrcode and Pillow to insert a logo into the centre of a QR code.
• QRcode.com — Error correction feature
  Official explanation of QR error correction levels and how much damage each level can tolerate.
• Scanova — QR Code Error Correction: How it works
  Practical guidance on when to use higher error correction, especially when adding logos.