QR Code Troubleshooting: Fixes for Every Common Problem

Most QR code problems fall into a small number of well-understood categories, and most have a clear, fixable cause. This guide is organized by symptom — find what's happening, jump to that section, and work through the checks in order.

Why won't my QR code scan at all?

When a code doesn't scan under any conditions, work through these in order, since they're listed roughly from most to least common:

1. Quiet zone violated — check that nothing (a border, a logo, cropped edges, another design element) is crowding the required blank margin around the code. See Quiet Zone Explained.
2. Contrast too low — light-on-light or two similar mid-tones will fail even in good lighting. See Contrast Recommendations.
3. Code printed too small for the scanning distance — see Small QR Codes below.
4. Camera can't focus — try moving the phone slowly backward and forward rather than holding a fixed distance; see Camera Recommendations below.
5. The image itself is corrupted or was resized incorrectly during printing — re-download a fresh copy directly from PXLA QR rather than a copy that's been resaved or resized multiple times.

"Invalid URL" error when generating a code

PXLA QR validates your input before generating anything, and rejects a small set of specific cases: empty input, input over 2000 characters, anything that isn't an http or https link (a javascript:, mailto:, or other non-web scheme), and input that doesn't resolve to a real-looking hostname (must contain at least one dot, like example.com). If you're seeing this error, check for a typo in the domain, an accidentally included leading/trailing space, or a stray character copied along with the URL from another source. See URL Validation for the complete rule set.

The printed QR code looks blurry

Blur almost always comes from one of two places: the printing process itself, or a resizing step before printing. Check that you're not stretching the image non-proportionally (different horizontal and vertical scale distorts module edges), that you're printing from the original downloaded file rather than a screenshot or a copy that's been resaved multiple times (each re-save of a lossy format can soften edges further), and that your printer's resolution setting is reasonably high (300 DPI or better) for the print size you're using. If the code is being scaled up dramatically beyond its native 1024×1024 pixel resolution, some softening at very large sizes is expected — see Recommended Print Sizes for the scale at which this becomes noticeable.

The QR code is too small to scan reliably

Size needs to match scanning distance, not just fit the available space in a design. A code sized correctly for a poster viewed from six feet away will be far too small if it's actually printed at business-card scale. Use the one-tenth-of-distance rule in our printing guide, and remember that a longer encoded URL needs a larger minimum size than a short one, since more data means more (and smaller) modules packed into the same physical footprint.

The QR code opens the wrong page

A QR code always decodes to exactly the URL it was generated from — there's no possibility of it "drifting" to a different destination over time or between scans. If a code is opening somewhere unexpected, the most likely explanations are: the wrong URL was typed in originally (double-check by re-scanning and reading the exact link text your phone shows before opening it); the destination page itself has since redirected or moved (a server-side change, unrelated to the code); or you're looking at a different, older printed copy of a code than you think you are, especially if multiple versions exist from earlier design iterations.

My phone's camera won't recognize the code at all

If nothing happens when you point a camera at a code — no notification, no link preview, nothing — first confirm QR scanning is actually enabled: on iPhone, check Settings > Camera > Scan QR Codes (see our iPhone guide); on Android, try Google Lens directly as a universal fallback (see our Android guide) since default Camera app behavior varies by manufacturer. If scanning is enabled and still nothing happens, treat it as a Why Won't It Scan issue above — the code itself, not the phone, is the more common root cause.

Camera recommendations for reliable scanning

• Hold the phone steady — motion blur during the brief moment a camera focuses is a common, easily fixed cause of failed scans.
• Don't scan at an extreme angle — QR codes tolerate moderate tilt well, but a very oblique angle distorts the finder patterns beyond what the scanner can correct for.
• Use adequate lighting — very dim environments reduce the contrast a camera sensor can resolve; turning on a flashlight often helps more than moving closer.
• Avoid glare — glossy print surfaces or laminated cards can create a reflective hotspot directly over the code; tilt slightly to move the reflection off the code rather than getting closer.

Browser compatibility for generating codes

PXLA QR works in every current version of Chrome, Safari, Firefox, and Edge, on both desktop and mobile, since it relies only on standard, widely supported web APIs (see Is Generation Client-Side?). If the generator doesn't load or doesn't respond to the Generate button, first try a hard refresh (Ctrl+Shift+R or Cmd+Shift+R), then confirm JavaScript isn't disabled in your browser's settings, since generation genuinely requires it to run. Very old browser versions (more than a few years out of date) may lack support for modern JavaScript features the tool depends on — updating the browser resolves this in virtually all cases.