Checks / Links, canonical and speed
Oversized images
Images over 300 KB slow the page for visitors and crawlers on mobile connections.
img_oversized · Links, canonical and speed · Warning
What triggers it
A page has at least one image whose file is over 300 KB.
What to change
Compress the image, serve WebP or AVIF and size it to the space it fills.
Example
HTML to put in the page:
<img src="/img/blue-trail-800.webp" width="800" height="600" alt="Blue trail running shoe, side view">How to confirm the fix
- Run curl -sI <image url> | grep -i content-length: under 300,000 bytes
- Run a new crawl
How common it is
We have not measured how common this is on a sample of sites. Counts appear here when a study covers it.
About this check
| Check ID | img_oversized |
|---|---|
| Report section | Links, canonical and speed |
| Severity | Warning |
| How it is decided | Measured: read directly from the page or the server's response. |
| Added | Version 3, 19 October 2026 |
| Status | Measured in every report |
| Report gives the code | No, the fix is described in words |
Related checks
- hreflang alternate does not link back
- HTTP version does not redirect to HTTPS
- Internal links use #/ routes
- Internal links carry tracking or language parameters
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