How to Make a QR Code That Actually Scans
A QR code only works if every pattern in it follows the standard, from the corner squares to the error correction.
What is the QR Code Generator?
This tool encodes your text in QR byte mode at error correction level L, choosing version 1 to 4 automatically for up to 78 characters. It builds the finder, timing and alignment patterns, Reed-Solomon error correction, masking and format information in plain JavaScript, then draws the code on a canvas you can download. Longer text, non-ASCII characters beyond single-byte characters, and versions above 4 are not supported here.
How to use it
- Enter the text or link you want to encode
- Pick a module size for the downloaded image
- Generate the code and download the PNG
Worked example
Hello QR gives a version 1 code, 21 by 21 modules, with its mask pattern and dark-module count shown below the preview.
Why do some QR codes fail to scan?
They fail when a pattern is missing, the format information is wrong, or the code is too small or low contrast. A complete encoder, a quiet white border and a test scan before printing avoid most failures.
Frequently asked questions
Will this QR code scan with a phone camera?
Yes, for the supported range: it is a complete byte-mode code with error correction, finder patterns and format information, not a decorative pattern. Test it with your own camera before printing.
Why is there a character limit?
Versions 1 to 4 at level L hold at most 78 single-byte characters, so longer input is refused rather than silently cut off.