How a QR code actually encodes information
A QR code is a two-dimensional barcode that stores data as a grid of black and white squares, readable by a camera from any angle. Unlike a traditional barcode, which only reads in one direction, a QR code's three large corner squares let a scanner instantly determine orientation and size, even from an angled or rotated photo.
What makes QR codes especially reliable is built-in error correction: a meaningful percentage of the code, up to 30% on the highest correction level, can be damaged, obscured, or covered by a logo, and the code will still scan correctly. This is why you'll often see a logo placed in the middle of a QR code without it breaking; the code was generated with enough redundancy to absorb that loss.
How to generate a QR code with this tool
- Type or paste the text, URL, or other content you want encoded into the input box.
- Adjust the foreground and background colors if you want something other than plain black on white. Though high contrast between the two is important for reliable scanning.
- Use the size slider to set the output resolution, larger for print, smaller for on-screen use.
- The QR code preview updates live as you make changes.
- Download it as a PNG once you're happy with the result.
Generation happens entirely in your browser. Nothing you encode is sent to a server, which matters if you're generating a code containing sensitive information like a private link or personal details.
Design choices that affect whether a code actually scans
The single biggest factor in scan reliability is contrast between the foreground and background colors. A QR code in a light gray on white, or a color combination with similar brightness, is much more likely to fail, especially in bad lighting or when printed on lower-quality paper. Solid black on solid white remains the safest choice when reliability matters more than aesthetics.
Size matters relative to scanning distance: a code meant to be scanned from a few feet away (like on a poster or storefront window) needs to be considerably larger than one meant to be scanned up close (like on a business card or product label). If a code will be printed small, keep the encoded content short. Shorter data means a simpler, less dense pattern that's easier for a camera to resolve at a small size.
Common uses beyond just linking to a website
QR codes aren't limited to URLs. They can encode plain text, a pre-filled email address, a phone number that launches a dialer, or a Wi-Fi network's credentials in a format that lets a phone join the network automatically without typing a password. Restaurants commonly use them for digital menus, event organizers use them for ticket check-in, and businesses use them on packaging to link to setup guides or warranty registration.
Because a QR code is just data plus error correction, what it "does" when scanned is entirely up to what you encode. A URL will open a browser, a properly formatted string will trigger the appropriate action, and plain text will simply display as text.