Payment Codes on One Image

Features

• Merge two (or more) payment codes into one image
• Side by side or stacked
• ⚠️ Nothing is rescaled — original pixels only, because scaling destroys scannability
• Adjustable margin and gap (the margin is the quiet zone a scanner needs)
• Optional caption under each code, such as the wallet’s name
• Adjustable background, white by default (dark backgrounds break scanner edge detection)
• Codes of different sizes are each centred in their own cell
• If the canvas exceeds the browser limit it says how to shrink it rather than handing you a blank image
• Merged in the browser; the codes are never uploaded

How to use

1. Choose the first payment code, then the second (the order sets the layout order)
2. Pick side-by-side or stacked, and fill in the two captions if you want them
3. Adjust the margin and gap to taste (do not shrink the margin too far)
4. Download the merged PNG

FAQ

Why not scale both codes to the same size?

Because it destroys scannability — in a way you cannot see. A QR code is a grid of modules and scaling resamples it; enlarging merely softens the edges, but shrinking throws sampling points away. An 800px code reduced to 400px can leave a one-module stripe half a pixel wide, and the scanner is then guessing. Hence nothing is rescaled here. It is also why two codes of different sizes come out untidy: tidiness is secondary, scannability is the hard requirement.

Why leave so much white space?

Because the QR specification requires a clear margin around the code (the quiet zone, at least four modules wide) for scanners to find its edges. When two codes sit next to each other, the space between them serves as the quiet zone for both — leave too little and a scanner may merge them into one code or fail to find an edge. The default 32px is estimated for typical payment codes; if yours are large (1000px and up), scale it up proportionally.

Can I use a dark background?

No — scanning will fail. QR recognition depends on the contrast of dark modules against a light field: the scanner binarises the image, then looks for the code’s boundary and quiet zone. On a dark background the light quiet zone is gone and the boundary cannot be found. It is not “some phones struggle”, it is “it does not scan”. The option is there for the cases where you genuinely know what you are doing.