Developer
What Is a QR Code and How Do You Make One?
June 3, 2026 · 4 min read
QR codes are everywhere — menus, posters, business cards. Here's how they work and how to generate one for any URL or text in seconds.
QR codes went from a niche logistics tool to something you see on restaurant tables, event posters, and business cards daily. They're a fast bridge between the physical and digital world — point a camera at one and you're on a website, on a contact page, or viewing a menu in seconds.
How a QR code works
A QR code (Quick Response code) encodes text as a two-dimensional pattern of black and white squares. A phone camera reads the pattern and decodes it back to text — usually a URL, which the phone then opens. The squares aren't random: they encode data using a specific standard (ISO 18004) that any QR reader understands.
The three large corner squares help the scanner orient the code regardless of angle or rotation. The smaller squares encode the actual data. The white border (quiet zone) helps the scanner distinguish the code from surrounding content.
What you can encode
- A website URL — the most common use, takes people directly to a page.
- Plain text — a short message, a Wi-Fi password, a location description.
- Contact information (vCard format) — opens as a new contact on the phone.
- Email address or phone number — pre-fills a compose screen or dialler.
Size and print tips
For print, QR codes need to be at least 2 cm × 2 cm to scan reliably from arm's length. Business cards should use at least 1.5 cm. For posters meant to be scanned from a metre or more away, go larger — 5 cm or above. Always test before printing by scanning with multiple phones.
High-contrast black on white is the most reliable colour combination. Coloured QR codes can work but reduce scan reliability, especially in low light.
The error correction advantage
QR codes have built-in error correction. Even if up to 30% of the code is damaged or obscured, it can still be read. This is why you sometimes see QR codes with a logo or image overlaid in the centre — the code is designed to survive it. Higher error correction levels make the code more robust but also larger.
Generating a QR code takes a few seconds and requires no account or signup. Enter the URL or text, choose the size, and download a PNG or SVG — the SVG scales perfectly for print without pixelating.