QR Code Generator
Generate QR codes using an API with instant preview.
Turning text and links into a QR code
A QR code is a two-dimensional barcode that any phone camera can read. It is the quickest way to move a URL from a printed page, a poster, a menu or a packing slip onto someone's phone without them typing anything. Enter a link or any text, choose a size, and you get a scannable code you can download and print.
How to use the QR Code Generator
- Type or paste your Text / URL.
- Set the Size (px) — larger for print, smaller for screen.
- The code regenerates as you type.
- Test it with your own phone before printing anything in bulk.
Formula and a worked example
Data → error-correcting encoding → module grid → scannable image
QR codes carry Reed-Solomon error correction, which is why a code still scans with a logo over the middle or a corner scuffed. Shorter data means fewer modules and a code that scans from further away — another good reason to shorten long URLs first.
Worked example
A short link of around 20 characters produces a sparse, chunky code readable from a metre away on a poster. A 200-character URL packs in far more modules, so the same printed size needs the camera much closer.
Frequently asked questions
Do QR codes expire?
The code itself never expires — it is just an encoded string. What can break is the destination: if the URL stops working, so does the code.
What size should I print a QR code?
A rough rule is one centimetre of code for every ten centimetres of scanning distance. For a poster read at two metres, print it at least 20 cm across.
Can a QR code hold more than a link?
Yes — plain text, phone numbers, email addresses, wifi credentials and contact cards all work. Capacity runs to a few thousand characters, though shorter is more reliable.
Why will my code not scan?
Usually too small for the distance, too little contrast, or too much data packed into a small print size. Shorten the data and increase the size.
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