QR code guides
Straight answers about how QR codes work, what breaks them, and how to print them so they scan the first time.
In shortThese guides explain QR codes in general — the format, its limits, and how to use it well. They are not about any one product, and nothing on these pages requires an account or a purchase.
The basics
- What is a QR code?
A two-dimensional barcode that stores data in a square grid, readable by any phone camera.
- How do QR codes work?
Finder patterns, masking, and the error correction that lets a damaged code still read.
- Do QR codes expire?
Static codes never do. What breaks is the destination, the redirect service, or the print.
- Static vs dynamic QR codes
One is permanent and private, the other is editable and trackable. Neither is better in general.
- QR code error correction levels
L, M, Q, and H recover 7 to 30 % of a damaged code, at the cost of a denser pattern.
- How much data can a QR code hold?
Thousands of characters in theory; a few hundred is the practical limit for print.
- QR code vs barcode
A short number read in one direction, or a full address read in two.
- QR code vs NFC
A chip and a tap, or ink and a camera. Cost, range, and compatibility compared.
- The history of QR codes
From a car-parts factory in 1994 to every phone camera.
Scanning and troubleshooting
- QR code not scanning?
Size, density, contrast, quiet zone, or the link itself — a checklist to find the cause.
- How to scan a QR code
The built-in camera on iPhone and Android is enough. No app needed.
- Scan a QR code from a screenshot
Reading a code that is already on your own screen.
- Are QR codes safe?
A code is a hidden link. How QR phishing works and how to check before you tap.
- Track QR code scans for free
UTM parameters and your own analytics, with no redirect service.
Making and printing
- How to create a QR code for a website
The full sequence, including the testing step most people skip.
- QR code size for printing
The 10:1 rule, minimum sizes, DPI, quiet zone, and contrast.
- PNG vs SVG QR codes
Vector for print, bitmap for everything else — and when the difference matters.
- Can a QR code be colored?
Yes, within contrast rules. Dark on light, never inverted.
- QR codes with a logo
How a centre logo spends error correction, and how big it can safely be.
- QR codes on flyers and posters
Sizes for A5 to A2, placement on the page, and the call to action.
- QR codes in presentations
Sizing a code on a projected slide so the back row can scan it.
Specific situations
- QR codes on business cards
What to link to at 2 cm, and why vCard codes are a poor fit for print.
- QR codes for restaurant menus
Hosting, table-tent sizing, and the accessibility case for keeping paper.
- QR code for Google reviews
Finding the right review link, and staying inside Google’s rules.
- QR codes for YouTube
Watch links, youtu.be, Shorts, handles, playlists, and timestamps compared.
- QR codes for WhatsApp
A wa.me link that opens a chat with your number, with an optional message.
- QR codes for Google Forms
The right share link, and the sign-in setting that quietly loses responses.
- QR codes on packaging
Small sizes, curved surfaces, and destinations that outlive the product.
- Wedding QR codes
RSVPs, the wedding website, and a shared photo album.
- QR codes for real estate
Sign riders and window cards that open the listing or the tour.
Make one
- Free QR code generator
Paste a link, download a PNG or SVG. No account, nothing uploaded.
- Wi-Fi QR code generator
Guests join with one scan; the password never leaves your browser.
- Custom QR code with logo and colors
Brand colours and a centre logo, with the contrast and size limits enforced.
- URL to QR code
What exactly gets encoded, including query strings and length limits.
- Private QR code generator
How to verify that nothing leaves your browser.