Guide · 7 min read
How to Compress Product Images Without Losing Visible Quality
A practical explanation of image compression for online sellers: dimensions versus file size, JPEG quality settings, and a simple workflow that keeps photos sharp.
Why file size matters for sellers
Large image files slow down product pages, especially on mobile connections. Slower pages lead to more shoppers leaving before the page has finished loading, and many marketplaces also have per-file upload limits. The good news is that most product photos straight from a camera or phone are far larger than they need to be, so there is a lot of room to reduce size without any visible change.
Dimensions come first, compression second
There are two separate ways an image file gets smaller, and the order matters.
- Resize the dimensions. A modern phone photo can be 4,000 × 3,000 pixels or more. If the platform displays it at 2,000 × 2,000 at most, the extra pixels are never shown to anyone. Cropping and resizing to the target size often removes more than half of the file size on its own.
- Compress the result. Once the image is at its final size, JPEG compression reduces the data needed to store it. This is where the quality setting comes in.
Doing it in this order matters because compressing a huge image and then shrinking it wastes quality and time. Crop to the final shape and size first, then export once at a sensible quality.
Choosing a JPEG quality setting
JPEG quality is usually shown as a number from 0 to 100. It is not a percentage of the original quality; it controls how aggressively the encoder simplifies detail that the eye is less likely to notice.
- 90 to 100: very large files with little visible improvement over 85 to 90. Rarely worth it for web use.
- 80 to 90: the sweet spot for most product photos. Sharp edges and smooth gradients are preserved.
- 70 to 80: acceptable for thumbnails or lifestyle images, but look closely at fine textures and text.
- Below 70: blocky artifacts start to appear, especially around high-contrast edges and on plain backgrounds.
Check compression at 100 percent zoom on the area with the finest detail, such as fabric texture or printed text on packaging. If that area looks clean, the rest of the image will too.
Watch out for these common problems
- Banding on white or gradient backgrounds. Plain backgrounds show compression artifacts first. If you see faint rings or blocks, raise the quality slightly.
- Re-compressing a JPEG repeatedly. Every save at a lossy quality loses a little more detail. Keep your original and always export from it.
- Using PNG for photographs. PNG is lossless, which sounds better, but for photos it often produces files several times larger than a high-quality JPEG with no visible gain.
- Hidden metadata. Camera files can include location data and large embedded previews. Re-exporting from a canvas-based editor drops most of this automatically.
A simple workflow you can repeat
- Keep the original photo untouched in a separate folder.
- Crop to the platform's aspect ratio and export at the platform's recommended size.
- Export JPEG at quality 85 as a starting point.
- Inspect the most detailed area at full size; adjust quality up or down by 5 if needed.
- Use the same settings for the whole catalog so photos look consistent.
Image Ready follows this workflow in the browser: you crop and resize to a platform preset, choose JPEG or PNG and a quality level, and download the result. Your original file is not uploaded anywhere, so you can experiment with settings without creating copies on a server.