Performance fix guide
No Responsive Images (srcset)
Images lack srcset attributes for responsive sizing. Without srcset, mobile devices download full-size desktop images unnecessarily.
Issue ID: PERF-IMG-SRCSET-001
Severity: low
Impact: Low
Effort: M
Use this article when
- You need deeper remediation guidance than the issue card can show.
- You want CMS-specific steps before handing the fix to a developer.
- You want a repeatable re-check path after shipping the change.
What this issue is
Images lack srcset attributes for responsive sizing. Without srcset, mobile devices download full-size desktop images unnecessarily.
Why it matters
Images lack srcset attributes for responsive sizing. Without srcset, mobile devices download full-size desktop images unnecessarily. This affects load speed, Core Web Vitals, and how many visitors stay long enough to convert.
How we detect it
- FreeSiteAudit flags this issue when the rule for PERF-IMG-SRCSET-001 fails and the page evidence points to Dom body.
- You can usually confirm this by checking the page source or the relevant page settings inside your CMS.
Evidence examples
Check the affected page source, rendered output, or relevant CMS setting to confirm the missing or incorrect element.
How to fix it
- 1Add srcset attribute with multiple image sizes to <img> tags
- 2Use the sizes attribute to help browsers choose the right image
- 3Example: <img srcset="small.jpg 480w, medium.jpg 800w, large.jpg 1200w" sizes="(max-width: 600px) 480px, 800px">
- 4Many CMS platforms and image CDNs can generate srcset automatically
How to re-check it
- Check that key images have srcset with at least 2-3 size variants
Related tools
This issue is best verified with the full FreeSiteAudit crawl rather than a single-point mini tool.