The code stopped scanning after I added a logo

Fix it

1. 1
   Shrink the logo

   In Customize, drag the logo size down. Keep it under a fifth of the code's width. That is about 4 percent of its area, which is well inside what we measured as safe.

2. 2
   Give it a white box

   A logo with a solid white background reads better than a transparent one that blends into the modules.

3. 3
   Keep the corners clear

   The three big squares in the corners are how phones find the code. A logo that touches them fails on every phone.

4. 4
   Scan with two phones

   Different cameras tolerate different amounts. If either one misses, shrink again.

Dense codes and logos

The opposite of what everyone expects, and we measured it: a code carrying a longer web address survives MORE logo, not less. A denser code has more modules, so losing the few in the middle costs it a smaller share of the whole. A short link is the least forgiving.

• Coverage is area, and area is deceiving. A square covering 10 percent of the area has sides about a third of the code's width, which looks far bigger than the number sounds.
• At the strength we generate at, a circular logo on a short link was still readable every time up to 14 percent of the area. A square only to 10 percent, because its corners reach further.
• On a longer web address the same two went to 20 and 12 percent.
• A circle beats a square at the same area, every time, because the corners of a square land on modules a circle misses.
• There is no clean edge, only a grey zone. One setting read 13 percent of the time in our runs, which is a code that works in the office and fails on the street.

Those are decode numbers from a clean file, not a photograph of a printed card at an angle in bad light. Leave room under them.

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