Pixel
A pixel is one of the tiny squares of colour that make up a digital picture; image sizes are counted in pixels across and down.
What it means
Zoom far enough into a photo on a screen and it breaks into a grid of small squares, each a single colour. Each square is a pixel. A picture’s size is the count across by the count down, so one 1500 by 1000 is 1500 pixels wide and 1000 high. You will often see pixels shortened to px.
Every image rule a shop meets is written in pixels. Google asks for at least 500 by 500 on every product image from 31 January 2027.1 For product markup on a web page, it recommends images of at least “50K pixels when multiplying width and height”.2
More pixels means more detail, but only when they come from the camera. Pixels added by enlarging a small picture are estimates of what lies between the ones it had.
Think of it like this
Pixels are like the stitches in a cross-stitch picture: each one a single colour, and only together do they make an image. Count them across and down and you have the picture’s size.
For example
A product photo 1500 by 1500 holds 2,250,000 pixels. Its 160 by 160 thumbnail holds 25,600, about 1 for every 88 in the original. That is why the thumbnail falls apart when you zoom in.
Why it matters
Pixel counts decide whether a channel accepts a picture. Check both sides: an image 1200 by 400 holds 480,000 pixels and still fails a 500 by 500 rule, because it is only 400 high.
Not to be confused with
A tracking pixel, the kind an advertising platform asks you to add to your shop, is something else. It is a small piece of code that reports visits and sales, and it plays no part in your product pictures.
Sources
- Google Merchant Center Help. Merchant Center product data specification update 2026.
- Google Search Central. Merchant listing (Product, Offer) structured data.