How to add a logo to a QR code without breaking it

Why a logo does not break the code

Every QR code carries error correction: part of the pattern is redundant, so a scanner can rebuild modules it cannot read. There are four levels, L, M, Q and H, which let roughly 7, 15, 25 or 30 percent of the code be covered or damaged and still decode. A logo placed over the centre of the code covers some modules, and the error correction fills them back in. As long as the logo covers less than the level can recover, with a margin for the real-world damage the code will also meet, the scan succeeds.

What error correction cannot replace are the three large squares in the corners. Those are the finder patterns; the camera uses them to locate the code and work out its orientation before it reads anything. A logo that touches a corner square breaks the code regardless of the level. Keep the logo in the middle, which is why every serious generator puts it there and ours does not let you move it.

The three rules

• Set error correction to H. It gives the most room for a logo, at the cost of a somewhat denser code. For a dynamic code with a short link, that extra density is small and does not matter.
• Keep the logo to about a fifth of the code's area. That leaves most of the 30 percent allowance for scratches, dirt, glare and a mediocre print. A logo that fills a third of the code may scan on your screen and fail on the poster.
• Keep the contrast. The logo must not sit on a background that blends into the modules around it, and the modules themselves must stay dark on light. A light-coloured logo with a small clear border around it is the safest shape.

Step by step in QR Solutions

• Make the code: enter the destination, or open an existing dynamic code and choose to edit its design. The preview updates with every change.
• Set the colours of the modules and the background under Colours. Open the advanced colour settings and set the error-correction level to H.
• Under Logo, upload your logo as PNG, JPEG or SVG. The generator resizes it and places it in the centre.
• Set the logo size with the slider. Start around a fifth of the code and only go larger if you have a reason to.
• Scan the preview with your phone, from the screen. If it reads, download SVG for print or PNG for screens. The design is saved with the code; the destination stays editable afterwards.

Which logo works best

A simple mark beats a wordmark. A symbol or an initial in a circle reads at the size a logo gets inside a code; a full company name with a strapline does not, and it needs a wider area to be legible, which costs modules. Use the version of your logo designed for small sizes, the one you use as a favicon or an app icon, and give it a plain background or a thin white edge so it separates cleanly from the modules.

Colour is free: the logo may be any colour, because the scanner only cares about the modules around it. The modules may be a brand colour too, as long as they stay clearly darker than the background. A navy code with an orange logo on cream scans as well as black on white.

Test it the way it will be used

A branded code must be tested from print, not just from the screen. Print one at the final size, scan it from the real distance with two different phones, and once more after it has been handled and creased. If it reads every time, the logo is the right size. If it reads on one phone and not another, the logo is too large or the contrast too low; shrink it a step and test again. Thirty seconds of this saves a reprint.

The code stays dynamic throughout. Adding, changing or removing the logo never changes where the code goes, and redirecting the code later never changes how it looks. The design and the destination are independent, which is what lets you brand a code before you know where it will finally point.

Frequently asked questions