A logo in the center of a QR code makes it look like yours rather than a generic black square. The trick is adding the logo without breaking the scan. Here is how to do it well.
TL;DR Open the QR code with logo tool, enter your link, upload a logo, keep it to about a quarter of the code, then download a PNG or SVG. Test it before you print.
Why a logo can still scan
QR codes carry error correction, which is spare data that lets a reader recover the content even when part of the code is covered or damaged. At the high setting these tools use, a phone can still read the code with a modest logo sitting in the middle. Push the logo too large and you cross the limit, and the code stops scanning.
The rules that keep it readable
Keep the logo to roughly a quarter of the code’s area. Use a mark with clear edges and strong contrast against the code. Leave the three large corner squares, the finder patterns, fully visible, since a phone uses them to lock on. And keep the quiet margin around the whole code clear of clutter.
Pick the right file
A PNG with a transparent background drops cleanly into the center. A solid-background logo works too, as long as it does not blend into the code color. An SVG is ideal because it stays sharp at any size.
Test before the print run
This is the step people skip and regret. Print or display the styled code at the size you will actually use, then scan it with two or three different phones. If any of them hesitate, shrink the logo or raise the contrast and try again.
Make one now
The QR code with logo tool builds everything in your browser, so your logo and link never leave your device. Add your link, drop in the logo, style the colors, and download a PNG or SVG.