How to reduce image size without losing quality

Why file size matters

Every photo on a product page has to download before the shopper sees it. A single shot from a recent phone can be several megabytes, and six of them on one page means asking a customer to download the equivalent of a short video before they reach the price. On a weak connection, that is a blank page for several seconds.

Compression does not change the dimensions of the picture. It changes how the detail is stored, giving up fine information your eye barely registers in exchange for a much smaller file.

Step by step

1. Open the Image compressor and pick one or more photos from your device. JPEG, PNG and WebP are accepted.
2. Choose the output format: JPEG for ordinary photos, or WebP if you want a smaller file and need to keep a transparent background.
3. Move the quality slider. Values between 70 and 85 suit most product photos.
4. Compare the size before and after for each photo, then download.

Which quality should you pick?

There is no single right number, because how much a photo shrinks depends on what is in it. A product on a plain white background shrinks a lot. A busy picture, like patterned fabric or a rug, needs a higher quality to stay clean.

A practical rule: start at 80 and look at the result zoomed in on your phone. If you cannot see a difference, try 70. If blotches appear around edges or banding shows up in the background, step back. Your eye decides, not the number.

When the file gets bigger instead

This happens more often than people expect. If your photo was already well compressed and you save it again at high quality, the new file can come out larger than the original. The compressor shows you that result plainly instead of hiding it. When it happens, keep the original or lower the quality a little.

Things to keep in mind

• This compression deliberately gives up some detail, so always keep a copy of the original.
• PNG files are converted to JPEG or WebP. JPEG has no transparency, so transparent areas are filled with the background color you choose. If transparency matters, pick WebP.
• EXIF data such as location and camera model is removed because the image is redrawn. That is a bonus if you would rather not publish where a photo was taken.
• Tested limits: 40 MB and 50 megapixels per image, and up to 30 images at a time.

If the photo is also larger than your store needs, shrink the dimensions first with the Image resizer, then compress. A 4000 pixel wide photo shown in a 1000 pixel space carries wasted weight however hard you compress it.