QR code not working? 12 causes and fixes

Was the code deactivated by the generator?

This is the most common cause of a code that "used to work". Cause 1: trial ended. Many services deactivate dynamic codes when a free trial ends. Cause 2: subscription ended or payment failed. Some shut codes off the moment payments stop. Cause 3: code paused for going over a scan or code limit.

How to check: scan the code and read the address before opening. If it is a short link on a provider's domain, open it: an "inactive code" or "renew your subscription" page confirms it. Only that provider can reactivate the code. The free QR code guide compares providers' policies.

Is the destination broken?

• Cause 4: page deleted or moved on your site, returning a 404.
• Cause 5: shared document made private, such as a Google Drive or Canva link whose sharing changed.
• Cause 6: expired domain: the whole site is gone, sometimes replaced by a parking page.

With a dynamic code the fix takes a minute: change the destination in your account, nothing to reprint. With a static code, either put a page back at the old address (a redirect on your site) or reprint.

Is it too small or too dense?

Cause 7: too small for the distance. The common rule wants a width of one tenth of the scanning distance, never under 0.8 inch. A 1 inch code on a poster read from 6 feet will not scan. Cause 8: too dense. A long URL or full vCard multiplies modules: on a small print, each one gets too fine for a phone camera. A dynamic code, which holds a short link, fixes this. The size calculator gives the minimum size by distance and content.

Is the contrast too low?

Cause 9: colors too close. Pink on beige, gray on white, gold on cream: the phone cannot tell modules apart. Aim for very dark modules on a very light background, with a contrast ratio of at least 4.5:1. Cause 10: inverted colors (light modules on dark), which some older readers cannot read. Cause 11: no white margin, because text or artwork touches the code: the standard asks for 4 empty modules all around. The QR code checker measures all three from a photo or file.

Is it your phone?

Cause 12: a device setting or limit. Dirty lens, QR scanning turned off in the camera, Pro or Night mode on, Screen Time restrictions, a very old phone. Test with a second device: if it reads the code, fix the first phone's settings. Our guides cover iPhone, Android and Samsung.

Special case: codes on screens and in emails

A code shown on a TV, a slide or a monitor fails for different reasons than a printed one. Screen glare, low brightness, a dark mode that inverts the colors, or a code displayed for only three seconds in a slideshow all get in the way. Keep screen codes large (a quarter of the screen height for presentations), bright, and on screen for at least 15 to 20 seconds. In emails, remember that people usually read on the same phone they would scan with: always add a clickable link next to the code, or most readers will never use it.

A five-minute diagnosis

How do you fix it without reprinting?

If the code is dynamic and the provider is active, correct the destination and you are done. If the code is static and points to your own site, add a redirect from the old address to the new one. If a provider you no longer want to pay has deactivated the code, there is no lasting fix without reprinting: use that reprint to switch to codes that stay active when you cancel, as the QRTada lifetime guarantee provides.

How do you keep it from happening again?

1. Keep an inventory: for each printed code, note the piece, date, provider and destination.
2. Go dynamic for anything that may change, with a provider whose cancellation policy is in writing.
3. Watch your destinations: a page deleted during a site redesign is the silliest and most common failure.
4. Check your analytics: a code dropping from 50 scans a week to zero overnight signals a physical problem (sticker ripped off, poster removed) or a botched destination change.
5. Inspect outdoor pieces monthly: sun, rain and friction wear a code faster than you think.