Do QR Codes Expire? What Actually Happens After You Scan One
Scan an old QR code on a poster that's been up for two years and sometimes it works fine, sometimes it leads to a dead link, and sometimes the app just says it can't be read. People often assume the code itself has "expired," but that's not quite what's happening. A QR code is a pattern, and patterns don't age. What ages is whatever the pattern was pointing to, and that distinction explains almost every confusing QR code experience you've ever had.
A static QR code, generated once with the destination baked directly into the pattern, never expires. A dynamic QR code redirects through a third-party service that can change or disable the destination later, and stops working entirely if that service shuts down. Most "expired" QR codes are actually dynamic codes whose redirect service or destination page has gone away, not a failure of the QR pattern itself.
Why doesn't a QR code pattern itself ever expire?
A QR code is just a visual encoding of data, text, a URL, contact details, arranged into a grid of black and white modules according to a published specification. Once printed or displayed, that pattern is fixed. There's no clock inside it, no built-in mechanism for it to stop being readable after a certain date. If you generate a QR code that encodes plain text, that code will scan and produce the exact same text in ten years as it does today, assuming the physical print hasn't degraded.
So why do some QR codes stop working?
The confusion almost always comes down to the difference between a static and a dynamic QR code. A static code encodes its final destination directly, permanently, in the pattern itself. A dynamic code instead encodes a short redirect URL controlled by a third-party service, precisely so a business can update where the code leads without reprinting it, useful for changing a menu link or updating a marketing landing page. The tradeoff is that a dynamic code's usefulness now depends entirely on that redirect service staying online. If the company managing it shuts down, or the subscription lapses, every dynamic QR code they ever issued stops working simultaneously, even though each physical pattern is still perfectly intact and scannable.
Can a QR code point to a dead page even if the code itself is fine?
Yes, and this is the most common real-world cause of a "broken" QR code. A static code encoding a specific web address will always scan to that exact URL. If the business later deletes that page, redesigns their site without setting up a redirect, or lets their domain lapse, the QR code will scan successfully and take you straight to a dead link or an error page. The code did its job perfectly. The destination just isn't there anymore.
How much physical damage can a QR code actually survive?
QR codes are built with Reed-Solomon error correction, the same family of error-correcting math used to keep scratched audio CDs playable. At the highest error correction setting, Level H, a QR code can have roughly 30 percent of its data modules destroyed, obscured, or deliberately overprinted with a logo, and still scan correctly. This is why brands can safely stamp a logo in the middle of a QR code: the error correction absorbs that loss without breaking the scan, as long as it was generated with a high enough correction level to begin with.
If you're generating your own QR codes, choosing a higher error correction level is worth it for anything that will be printed small, exposed to wear, or have a logo placed over it. The QR code generator on this site lets you choose the error correction level directly, and produces static codes, meaning whatever you encode is permanent, with no third-party redirect service in the middle to fail later.
Frequently Asked Questions
Do QR codes expire after a certain amount of time?
A static QR code, one that directly encodes text or a URL, never expires on its own, the pattern itself is permanent. What can expire is whatever it points to: a web page can be taken down, a URL shortener link can be deactivated, or a dynamic QR service can deliberately stop redirecting an active code.
What's the difference between a static and a dynamic QR code?
A static QR code has the destination baked directly into its pattern, permanently. A dynamic QR code instead encodes a short redirect URL controlled by a third-party service, which means the destination can be changed later, but it also means the code stops working entirely if that service shuts down.
Can a QR code stop working even if the pattern is undamaged?
Yes, if it's a dynamic QR code and the service managing the redirect goes offline, or if it points to a webpage that's been deleted or moved. The physical pattern can be perfectly scannable and still lead nowhere useful.
How much damage can a QR code survive and still scan correctly?
Depending on the error correction level chosen when it was generated, up to roughly 30 percent of the code's data can be destroyed, obscured or overprinted (at the highest level, Level H) and it will often still scan correctly, thanks to Reed-Solomon error correction built into the QR standard.
Is it safe to scan an old QR code found on a poster or a sticker?
Scanning it is safe, but be cautious about what you do after. A QR code can just as easily point to a malicious link as a legitimate one, and an old or damaged sticker is sometimes evidence of tampering, where a fraudulent code has been physically stuck over a genuine one.
Do QR codes generated on this site expire or rely on a redirect service?
No. The QR code generator here produces fully static codes, generated entirely in your browser, with the destination baked directly into the pattern and nothing routed through a third-party redirect service that could later go offline.