AHREFS reporting images too large. Is this really an issue?

Technical Q&A
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Topic summary

A user receives Ahrefs reports flagging images as too large, but believes this is inaccurate since Shopify’s Dawn theme automatically serves resized WebP versions that are much smaller than the original PNG files.

Investigation findings:

  • Upon examining a sample product page, some PNG files are indeed being served directly through Shopify’s CDN without automatic WebP conversion
  • The images in question are approximately 400KB in size
  • Despite the file sizes, page load performance appears acceptable even on slower connections

Recommendation:

  • Pre-compress images using tools like TinyPNG before uploading to Shopify
  • However, given the current file sizes and acceptable load times, optimization is suggested but not critical

The discrepancy appears to stem from Shopify not converting all image instances automatically, rather than being purely an Ahrefs reporting issue.

Summarized with AI on November 1. AI used: claude-sonnet-4-5-20250929.
1

We are getting reports from AHREFs saying our images are too large. Looking at their report, they are looking at the base images in png format. However, when shopify serves the images, they are generally resized down, and almost always webp format, and are much smaller.

We are using Dawn.

Is this just a problem on how AHREFs interprets the images? It doesn’t seem to reflect the reality of how the pages actually load.

Thanks.

2

Do you mind sharing a link to a page with an example of the images. I can take a look.

3

https://www.gryphonsmoon.com/products/tree-of-life-window-sticker-wst-s53

4

Hey,

Thanks for sending that through. I’ve taken a look, and the images look fine—though perhaps they could be optimised a little? I can see the .png files in the code, and if you open the actual image, they’re being linked from here:
https://www.gryphonsmoon.com/cdn/shop/files/WST-S53-Tree-Of-Life-Window-Sticker.png?v=1735713316&width=550
So it looks like Shopify isn’t converting all instances automatically.

I’d always recommend running any images through a compressor/optimiser tool such as TinyPNG before uploading.

That being said, the images are only about 400KB, so I wouldn’t be too worried if you didn’t want to make any changes. My internet is terrible, and the site still loaded quickly.

Cool stickers, by the way! :slightly_smiling_face: