Guide
How Shopify Serves Images After Upload
Shopify’s CDN often delivers a resized WebP even when you uploaded a JPG. Prepare the master file, then use the format, width, and alt-text guides.
Quick answer: Shopify’s CDN can resize your upload and serve WebP to browsers that accept it. That does not replace a sensible master file. Resize to the width your theme displays, compress that file, and upload a format the admin accepts—usually JPG or PNG. Format choice, product widths, and alt text already have their own guides. This page only covers the handoff.
What Shopify changes after upload
When a shopper opens your store, Shopify’s image CDN often sends a smaller derivative, commonly WebP, instead of the exact file you uploaded. The original stays in the admin. Themes request sizes through srcset, so one upload can feed several widths.
You still control the master. A 4000 px camera file makes those derivatives slower to generate. Start from a file that is already close to the largest size the theme displays.
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Try our Image Compressor
Reduce image file size while keeping good visual quality.
Widths and compression targets: Shopify product image widths.
The store workflow for product photos: optimize product images for Shopify.
What to prepare before you upload
Crop to the product frame you want in the gallery.
Resize to the theme’s large image width. Check the theme—don’t copy a pixel size from a generic chart.
Export JPG for photos, or PNG when you need a transparent background.
Compress the export so the master is not a raw camera file. Use the image compressor in your browser if you want a smaller JPEG before upload.
Do not upload AVIF or HEIC unless you have confirmed the theme and the admin accept them. If you only have one of those files, convert it first with AVIF to JPG or HEIC to JPG.
Where format and alt text live
This page does not decide JPG vs PNG vs WebP vs AVIF for every site. Use JPG, PNG, WebP, or AVIF for websites. If you only need the three common photo formats, use PNG vs JPG vs WebP.
Filenames and alt text are in image alt text and filenames. Describe the product. Don’t paste a keyword list into the alt attribute.
FAQ
Does Shopify convert images to WebP?
Often yes, for the file the browser downloads. Modern themes request an optimized derivative from the CDN. Your upload can still be a JPG or PNG.
Should I upload AVIF to Shopify?
Only if your theme and the admin accept it. Many stores are safer uploading JPG or PNG and letting the CDN create the WebP derivative.
Do I still need to compress if Shopify optimizes images?
Yes. A CDN derivative does not fix a huge master. Resize and compress before upload so the source is already close to what the theme displays.
Where should I set the product image width?
In the theme’s image size settings, then export the master to that width. The width guide is Shopify product image widths and compression.