How to Make a QR Code: Static vs Dynamic, Wi-Fi and Print Size
Make a free QR code for a link, Wi-Fi network or contact, choose between static and dynamic codes, and size it correctly for flyers, posters and signs.
By Awais, Founder and editor-in-chiefPublished
To make a QR code, open a QR code generator, choose what the code should do (open a link, join Wi-Fi, save a contact), enter the details, and download the image as PNG or SVG. Test it with your phone camera before you print, and make it at least 2 cm (0.8 in) wide, or about one tenth of the distance people will scan it from.
This guide explains the choice between static and dynamic codes, how Wi-Fi codes work, and how to size and print a code that scans first time.
How to make a QR code in four steps
- Open the QR Code Generator.
- Pick a type: URL, Wi-Fi, Contact or another option, and fill in the fields. The preview updates as you type.
- Optionally change the colours, add a logo, or adjust the error correction level in the design settings.
- Scan the preview with your phone, then download PNG for screens and documents or SVG for print.
Our generator makes the code in your browser. The link, Wi-Fi password or contact details you type are not sent to a server, and the code has no expiry date.
Static vs dynamic QR codes
This is the most important choice, and many people only discover it when a printed code stops working.
| Static QR code | Dynamic QR code | |
|---|---|---|
| What is stored in the code | Your actual link, text or Wi-Fi details | A short link to the provider’s server, which redirects to your link |
| Can you change the destination after printing? | No | Yes |
| Scan statistics | No | Yes, collected by the provider |
| Expires? | Never | Can stop working if the subscription ends or the provider closes |
| Cost | Free | Usually a monthly or yearly fee |
| Privacy | No third party sees scans | The provider sees every scan |
Choose static for anything permanent: Wi-Fi details, contact cards, a link to your own website, or a product manual. If you want statistics, point a static code at a page on your own site and use your own analytics.
Choose dynamic only if you truly need to change the destination after printing, such as a menu that moves between websites, and you trust the provider to stay in business. Before you sign up, check what happens to the code if you stop paying.
How to make a Wi-Fi QR code
A Wi-Fi code lets guests join your network by pointing their camera at it, with no typing. Inside, it stores a short text in a widely supported format:
WIFI:T:WPA;S:CafeGuest;P:sunny-teapot-42;;T is the security type (WPA, WEP, or nopass for an open network), S is the network name and P is the password. If the name or password contains a semicolon, comma, colon, backslash or double quote, it must be escaped with a backslash. A generator does this for you.
To make one:
- Choose Wi-Fi in the generator.
- Type the network name exactly as it appears on your devices, including capital letters and spaces.
- Choose the security type. Most home and office routers use WPA2 or WPA3; pick WPA.
- Enter the password and test the code with a phone that has not joined the network before.
The password is stored in the code as plain text, so anyone who can photograph the code can read it. Use a separate guest network for a code on public display, and give it its own strong password. A random passphrase from our Password Generator works well, because nobody has to type it. See how to create a strong password for what makes one strong.
How big should a printed QR code be?
The 10:1 rule of thumb
A widely used rule is that a code should be at least one tenth as wide as the scanning distance. It is not part of the QR standard, and phone cameras vary, but it is a reliable starting point:
| Where it will be scanned | Typical distance | Minimum code width |
|---|---|---|
| Business card, product label | 15–20 cm | 2 cm (0.8 in) |
| Flyer, menu, table card | 25–30 cm | 3 cm (1.2 in) |
| Poster on a wall | 1–2 m | 10–20 cm (4–8 in) |
| Shop window | 3 m | 30 cm (12 in) |
| Billboard or banner | 10 m | 1 m (40 in) |
Never go below about 2 cm, even for close scanning. Scale up if the code will be scanned in poor light, through glass, or at an angle.
More data means smaller squares
A QR code is a grid of small squares called modules. The smallest code (version 1) is 21 × 21 modules and the largest (version 40) is 177 × 177. The more you store, the more modules you need, and at the same printed width each module becomes smaller and harder to read.
| Content | Characters | Effect |
|---|---|---|
Short link: https://example.com/menu |
24 | Small, open grid; easy to scan |
| Long tracking link with parameters | 150+ | Dense grid; needs a bigger print |
| Contact card with address and notes | 300+ | Very dense; print large or trim fields |
At its limit, a version 40 code at the lowest error correction level holds 7,089 digits, 4,296 alphanumeric characters or 2,953 bytes of data. You won’t get close to that in practice, but the lesson is the same: shorter content makes better codes. Use a short URL from your own domain where you can.
Leave a quiet zone
The standard calls for a blank margin, the quiet zone, of four modules on every side. Don’t place text, borders or busy backgrounds right up against the code. A white margin is part of the code, not wasted space.
Error correction and logos
QR codes contain spare data so they still scan when part of the code is dirty, torn or covered. There are four levels:
| Level | Damage the code can recover from |
|---|---|
| L (Low) | About 7% |
| M (Medium) | About 15% |
| Q (Quartile) | About 25% |
| H (High) | About 30% |
Higher levels make the code denser, so use M for most printed material and H when you put a logo in the middle. Keep the logo small, roughly a fifth of the code’s width at most, and test it on several phones. A logo with a transparent background looks cleaner; see how to remove a background from an image if yours sits on a white box.
These figures come from Denso Wave, the company that invented the QR code, on its error correction page and version page.
Printing tips
- Use strong contrast. Dark modules on a light background. Inverted codes (light on dark) and pale colours fail on some phones.
- Print vector files. SVG stays sharp at any size; a small PNG stretched for a poster turns blurry.
- Avoid shiny surfaces and curves. Glare on laminated menus and codes wrapped around bottles can block scanning.
- Add a call to action. “Scan to see the menu” tells people what they will get and builds trust.
- Test the final print, not just the screen preview, from the real distance and in the real light.
Scanning a QR code
Current iPhones and most Android phones scan QR codes from the built-in camera app: point the camera at the code and tap the link that appears. Some Android phones use Google Lens for this. Before you open a link from a code in a public place, check the address shown; a sticker placed over a genuine code can send people to a fake payment or login page.
FAQ
Do QR codes expire?
Static codes never expire, because the data is inside the pattern. Dynamic codes depend on the provider’s redirect service and can stop working if the subscription ends.
Can I change a QR code after printing?
Not a static one. If you might need to change the destination, point the code to a page on your own website and change that page instead.
Why won’t my QR code scan?
The usual causes are a code printed too small, too little contrast, a missing quiet zone, too much data, or a logo that covers too much. Make it bigger, simplify the content, and test again.
Is it safe to put my Wi-Fi password in a QR code?
Anyone who sees the code can read the password, so use it for a guest network rather than your main one, and change the password if the code is no longer needed.