Images too large for phones
Images download far wider than they show on a phone, wasting data and slowing the page.
Checked on: every page the audit scans · Zolvio’s check: “Images too large for mobile”
Why it costs you sales
On a phone, an image shown 350 pixels wide doesn’t need a file thousands of pixels wide. Shoppers wait for, and pay data for, pixels they never see.
How Zolvio detects it
Zolvio opens the page at 375 pixels wide, compares each image’s real size with the size it’s shown at, and reads the size of its file. An image at least 1,000 pixels wide that downloads at least 6 times wider than it shows, twice what even a high-resolution phone screen needs, in a file of 100 KB or more, flags the page. Images shown narrower than 50 pixels, images in pop-ups and chat widgets, vector (SVG) images and placeholders drawn inline are ignored, and repeated carousel slides count once. The finding lists them (up to ten), with their file sizes.
This is a direct measurement, so it’s reported on every plan, including Free and audits with AI turned off. With AI review on, the AI agent also checks it against the audit’s evidence before it reaches your issue list.
How to fix it
- Find the images the finding lists: they’re usually in a custom HTML or Liquid block, or added by an app.
- Serve them at the size they show: Shopify’s image_url filter takes a width, and image_tag with widths and sizes lets phones download a smaller file. Or use the theme’s own image block, which sizes images for you.
- For images inside product descriptions, upload a smaller version in the product admin.
In Zolvio: on paid plans with AI turned on, the guided fix writes these steps for your own store and theme: where to click in Shopify admin or the theme editor, or which file to open, the line to find and the code to add. Each file opens in Shopify’s code editor. Zolvio never edits your theme: you make the change, then Verify fix checks your published theme for code changes (or you mark it fixed), and later audits confirm the problem is gone.
Common questions
Why does “Images too large for phones” cost a Shopify store sales?
On a phone, an image shown 350 pixels wide doesn’t need a file thousands of pixels wide. Shoppers wait for, and pay data for, pixels they never see.
How does Zolvio detect “Images too large for phones”?
Zolvio opens the page at 375 pixels wide, compares each image’s real size with the size it’s shown at, and reads the size of its file. An image at least 1,000 pixels wide that downloads at least 6 times wider than it shows, twice what even a high-resolution phone screen needs, in a file of 100 KB or more, flags the page. Images shown narrower than 50 pixels, images in pop-ups and chat widgets, vector (SVG) images and placeholders drawn inline are ignored, and repeated carousel slides count once. The finding lists them (up to ten), with their file sizes.
How do I fix “Images too large for phones” on Shopify?
Find the images the finding lists: they’re usually in a custom HTML or Liquid block, or added by an app. Serve them at the size they show: Shopify’s image_url filter takes a width, and image_tag with widths and sizes lets phones download a smaller file. Or use the theme’s own image block, which sizes images for you. For images inside product descriptions, upload a smaller version in the product admin.
Related
- HighSpeedImages much larger than they’re shown
- MediumMobilePage scrolls sideways on mobile
- HighMobileText too small to read on mobile
- HighMobileNo mobile navigation menu
Documentation
- How audits work — What an audit scans and how findings become issues.
- Guided fixes — Step-by-step fixes written for your theme, with links into the code editor.
- Heatmaps — See where shoppers tap and how far they scroll, on mobile and desktop.