Most QR code failures come down to one of five causes: low contrast, a missing quiet zone, print damage, a dead destination URL, or an expired dynamic link. Match your symptom (won't scan, scans but dead link, works on iPhone but not Android, or stopped working after it used to work) to the cause, and the fix is usually a one-minute change.
Why is my QR code not working? Start with the symptom
Diagnose by symptom, not by app. Every failed QR code falls into one of four buckets, and each bucket points to a different fix: the camera won't scan at all, it scans but nothing happens, it scans on one phone but not another, or it used to work and stopped. Match your symptom below before changing anything.
The four failure symptoms
- Won't scan at all. Usually a camera or image problem: low contrast, print damage, or a dirty lens.
- Scans but the link is dead. The code decoded fine; the destination URL expired or was typed wrong by the creator.
- Works on iPhone, not Android. Often a settings issue. Check that QR scanning is enabled in your camera app per Android Help.
- App-specific failure. Zelle, PSN, and similar codes only work inside their own app, not your camera.
Quick diagnosis table
| Symptom | Likely cause | First fix |
|---|---|---|
| Camera won't scan | Contrast or print damage | Reprint larger, darker |
| Scans, dead link | Expired destination URL | Ask creator for a new code |
| iPhone yes, Android no | Camera settings | Enable QR scan in camera settings |
| App-only code fails | Wrong app or expired session | Open it inside the issuing app |
If you're on the creator side and the code itself is the problem, regenerating it is often faster than debugging it. And once it works, a tool like answerplz lets you scan and get the answer in one click without copy-pasting links between windows.
Why won't my QR code scan at all?
When a code refuses to scan at all, the cause is almost always on the design or print side, not in the app doing the scanning. Three creator-side mistakes cover most cases: low contrast, a missing quiet zone, and physical damage to the printed code.
Low contrast and inverted colors
Scanners read the dark modules against a light background. Dark text on a light background works; light text on a dark background often does not, because many cameras and readers are tuned to a dark-on-light pattern. If you want colored codes, keep the modules noticeably darker than the background, and skip gradients that blur the difference. White-on-black inversions fail often enough that you should treat them as the first thing to test.
Quiet zone too small
The quiet zone is the empty margin around the code, and it is part of the spec, not decoration. Without it, the scanner cannot tell where the pattern starts and stops. Four modules of clear space on every side is the safe default; a tight crop or a background color bleeding into the edge is enough to break scanning.
Print damage, glare, and curvature
A scratched sticker, a glossy laminate catching light, or a code wrapped around a bottle can all block a scan even though the code itself is correct. Test the same file printed flat on matte paper: if that scans, the file is fine and the physical presentation is the problem. This is also where a screenshot-answer tool earns its keep. Point answerplz at the failed code on your screen, hit the global hotkey, and get a diagnosis in one click, no copy-paste or switching windows. We compare how that flow stacks up against Crade in our answerplz vs Crade breakdown.
Why is my QR code not working on Android specifically?
Most Android scan failures come down to three settings: the QR toggle inside your camera app, which scanning engine is doing the work, and screen brightness when you're scanning a code off another phone.
Camera app QR toggle
Many Android camera apps ship with QR scanning turned off by default. Open the Camera settings (gear icon) and look for "Scan QR codes" or "Lens" — flip it on. Without it, the camera sees the code but never tries to decode it.
Lens vs native camera
If your stock camera won't scan, long-press the code in the viewfinder or open Google Lens directly. Lens decodes codes the native viewfinder misses, especially small or slightly blurry ones. Some apps also have their own scanner: Zelle's QR payments, for example, run inside participating banking apps, so scan there rather than through your camera (Zelle help).
Screen brightness and screenshot scanning
Scanning a code shown on another phone? Raise that screen's brightness and turn off dark mode — inverted colors break most decoders. If the code is in a screenshot, crop tightly around it; extra clutter slows detection. For codes on your own screen, an overlay tool like answerplz reads them without a screenshot at all.
Why is my QR code not working even though it scans?
A scan that succeeds but produces nothing useful means the problem moved downstream: the code itself is fine, but what happens after the scan isn't.
Dead or wrong destination URL
The camera reads the code, the phone opens a link, and the link goes nowhere. This is the most common "scans but does nothing" case: the destination URL expired, the page was deleted, or the code was generated pointing at the wrong address. Test it by opening the URL from the code on another device. If it 404s there too, the fix is on the creator side, not your camera.
Redirect and tracking failures
Many QR codes route through a redirect service that logs the scan before sending you onward. If that service is down, slow, or the campaign behind it was shut off, the scan stalls or dies at the redirect even though the printed code is perfect. You'll usually see a timeout or a generic error page.
Scanner app can't handle the content type
Some codes don't hold URLs at all. Wi-Fi credentials, vCards, event invites, and app-specific codes need the scanning app to know what to do with the payload. If your built-in camera scanner doesn't support that content type, it scans, shows raw text or nothing, and stops. Trying a different scanner app often resolves it instantly.
If you're scanning codes like this regularly and want the answer without copy-pasting into a chatbot, that's what answerplz is for: it reads your screen and answers in context, one click. Recent fixes and improvements are tracked in the changelog.
Why is my Canva QR code not working after I download it?
Download compression and resizing
Canva exports go through compression, especially as JPG, and that can blur the small modules that make a QR code scannable. Resizing the QR element inside your design is the bigger culprit: shrinking it below roughly 2 cm in print, or dragging it out of proportion, breaks the pattern. Re-download as PNG at the highest quality, keep the QR square, and test-scan it before printing.
Wrong link entered at generation time
If it scans cleanly but lands nowhere, the URL typed into Canva's QR generator is probably wrong. Check for typos, missing, or a link to a page you later unpublished. Canva codes are static, so editing the design won't change the destination. Regenerate with the correct URL, and if you want to verify what a code actually points to without scanning it with your phone camera first, a screen assistant like answerplz reads it in one click (see how it compares to Jarvis: https://answerplz.com/vs/jarvis).
Why is my Zelle, PSN, or Facebook QR code not working in the app?
App-generated codes fail for app-specific reasons, not scanning problems. If the code scans but the app rejects it, the cause is usually on the app's side.
Zelle QR codes and bank support
Zelle QR codes only work inside apps that support Zelle, and both people need eligible accounts at participating banks. If your bank's app shows an error after scanning, the fix is usually updating the app or contacting your bank, since Zelle itself is run through the banks. Try regenerating the code from the payment screen rather than reusing an old screenshot.
PSN code not working: expired or already redeemed
PlayStation voucher codes fail most often because they were already redeemed, entered wrong, or region-locked to a different account. PlayStation Support's troubleshooting page lists the error codes for invalid or already-used vouchers. If the code came as a QR code, scan it, then type the revealed code manually to rule out misreads.
FB code not working: two-factor and login codes
Facebook login QR codes and two-factor codes expire within minutes. Generate a fresh code and confirm your phone's clock is set to automatic, since a wrong clock breaks time-based codes.
Why did my QR code stop working after it used to work?
A QR code that scans but goes nowhere usually means something behind it changed, not the code itself. Check these three things in order.
Dynamic QR subscription expiry
Many "dynamic" QR codes are tied to a paid account. When the subscription lapses, the redirect service stops forwarding the code and it dead-ends, even though the printed pattern still scans fine. If your code was generated inside a tool that charges monthly, log back in and check your plan status before blaming the print.
Destination page moved or deleted
The code only stores a URL. If the page was renamed, deleted, or the site moved to a new domain, the link breaks while the code still scans. Test the URL in a browser by typing it manually. If it 404s, you need a new code pointing at the live page.
Garage code not working: sensor and signal issues
Garage and door-opener QR codes fail differently: the code is fine, but the sensor or receiver it triggers has drifted. Dead sensor batteries, misaligned readers, or a weakened signal all show up as "the QR stopped working." Swap the sensor battery first, then re-pair the device, and only regenerate the code if the reader itself is replaced.
How do I fix a QR code that scans but opens the wrong or dead link?
Test with two scanners
If the code scans but the link fails, the QR itself is fine and the destination is the problem. First, confirm what the code actually contains: scan it with your phone's camera and a second scanner, such as a different device, and compare the URL both show. If both show a typo, an http:// link where the site needs, or a URL to a page that no longer exists, you have your cause.
Regenerate with the corrected URL
QR codes are not editable, so fixing the link means generating a new one with the corrected URL. Copy the working URL straight from your browser's address bar, paste it into your generator, and test the new code with both scanners before printing or sharing it. If the code points to a login-gated page, like a Facebook security setting, confirm the page is reachable when logged in: Facebook documents its login-code flow in the Help Center, and anything behind authentication will look "dead" to a scanner that opens a logged-out browser.
When should I regenerate a QR code instead of troubleshooting it?
Regenerate when the problem is baked into the code itself: a dead destination URL, a typo in the encoded link, or a print so damaged that contrast and quiet zone are gone. No amount of rescanning fixes wrong data.
Fix, don't regenerate, when the code is fine and the environment is the problem: dirty camera lens, low light, glare, or an app that needs an update.
The cutoff test: if two different phones on two different apps both fail on the same printed code, the code is the problem. Print a fresh one. If one phone fails and another scans it, troubleshoot the phone.