How to test a QR code before you print it
Published · by Support Team
Most "my QR code doesn't work after printing" stories have the same shape: the code was never tested the way it would actually be used. It scanned fine as a 400-pixel image on a laptop, then failed at 15 mm on a glossy business card under a restaurant's warm lighting. Every problem below is cheap to catch before the print run and expensive after it. Budget five minutes.
1. Scan it on screen with a real phone
Open the final artwork at the size it will print and point a phone camera at the screen. Use the built-in camera app, not a special scanner app, because that is what your customers will use. Then do it again with a phone from the other ecosystem (iPhone and Android read codes slightly differently). If it does not scan on screen, no amount of printing will help.
2. Read the destination before you tap it
The camera shows the decoded address before opening it. Read it. This is the
moment you catch exmaple.com, an http:// that should
be https://, a link to a staging site, or a personal Dropbox
link. If the address is a short link on another domain
(bit.ly, qrco.de, qrcr.us/r/), the
code is dynamic; make sure
you know what keeps that redirect alive (see step 6).
3. Print one proof at the real size
An office printer is fine. Cut it out, put it where the final piece will live, and scan from the distance a customer would: across a table for a menu, arm's length for a business card, a couple of metres for a poster. The rule of thumb is scan distance ÷ 10 = minimum code width. A code read from 30 cm wants to be at least 3 cm wide; one read from 2 m wants 20 cm. Never go below about 2 cm (0.8 in) regardless.
4. Check the quiet zone and contrast
The code needs a clear margin on all four sides, at least the width of four of its small squares, with nothing printed in it. Designers routinely crop this or run a border into it. Then look at contrast: dark modules on a light background, and keep the difference strong. Light grey on white, dark blue on black, or a code laid over a photograph are the usual failures. Inverted codes (white on dark) work on most modern phones but not all; if you can avoid it, do.
5. Consider the finish and the surface
Gloss lamination and glossy stock reflect overhead lights straight back into the camera; matte is far more forgiving. Curved surfaces (bottles, cups) distort the grid; keep the code small enough to sit on the flattest part. Outdoors, ink fades and vinyl peels; a slightly larger code with more error correction survives longer. If the code has a logo in the middle, confirm the generator raised the error-correction level to compensate and rescan the proof.
6. Make sure it will still work next year
This is the check people skip, and it is the one that costs the most. If the code is dynamic, ask who is keeping the redirect alive and on what terms. Trial codes stop when the trial ends. Subscription codes stop when the subscription does, sometimes for every code on the account at once. We wrote up the whole failure mode in do QR codes expire? If you would rather not think about it again, use a code that cannot lapse: a static code to a page you control if the destination is truly permanent, or a pay-per-scan dynamic code like QRCR.us, where there is no plan to expire, credits never expire, and a code that runs dry pauses instead of dying.
The two-minute version
Scan the artwork on screen with two phones. Read the address. Print one at size and scan it from where it will be read. Confirm a clear margin, strong contrast, matte finish. Know what keeps the redirect alive. Then print the run.
On QRCR.us every new code redirects free for its first 24 hours, which is long enough to run this whole checklist on a real code, including a real printed proof, before you spend anything.
- Try it on a real code Every QRCR.us account starts with 25 free scans, and every new code redirects free for its first 24 hours — no card required. Create a dynamic QR code and see it work before you spend anything.