A QR code on a counter or receipt is a simple, low cost way to collect reviews from customers who are physically in front of you, but it solves a different problem than a text or email request, and works best alongside one rather than instead of one.
What a review QR code actually is
It is simply a scannable code that opens a direct link to your Google review box on a customer's phone camera. There is no app required and nothing to install, the customer scans it with their regular camera and it opens straight to where they can write a review.
Where they work best
QR codes shine in physical, in person settings: a till counter, a printed receipt, a sign near the exit, a card handed over at the end of a visit. They are cheap to produce, need no ongoing cost once printed, and work well for businesses with a steady flow of walk in customers like cafes, salons, and retail shops.
Where they fall short
A QR code only works if the customer happens to notice it, has their phone out, and chooses to act in that exact moment, which is a much smaller window than a text message that arrives directly and waits until the customer is ready to act on it. They also do nothing for customers who were served remotely, by phone or online, since there is no physical location to place the code. And once printed, the link is fixed, updating it later means reprinting the material, unlike a digital link that can be changed centrally at any time.
Pairing a QR code with a direct request, not replacing it
The strongest setup uses both: a QR code for the customer standing in front of you right now, and an automatic text or email request for the broader base of customers who were not in a position to scan anything at the point of service. Treating a QR code as the entire review strategy leaves out everyone who was not physically present at the till, which for most businesses is the majority of customers.