fix: cap srcset against naturalWidth instead of currentWidth#1036
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selul merged 1 commit intoCodeinwp:developmentfrom Mar 25, 2026
Merged
fix: cap srcset against naturalWidth instead of currentWidth#1036selul merged 1 commit intoCodeinwp:developmentfrom
selul merged 1 commit intoCodeinwp:developmentfrom
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The srcset detector was capping 1x DPR variants at the CSS-rendered width at profiling time, not the image's natural pixel width. This caused blurry images on viewports wider than the profiling screen. Before: A 2560px image profiled on 1440px screen would only generate srcset entries up to 1440w for 1x DPR, causing upscaling blur on larger screens. After: The srcset is capped at the image's naturalWidth, ensuring all available resolution is used regardless of profiling viewport. Fixes Codeinwp#1030
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Summary
Fixes #1030 - srcset capped at profiling container width, causing blurry images on wider viewports.
Problem
When Optimole's JS page profiler measures an image on a desktop screen (e.g. 1440px wide), it stores srcset entries capped at that container width. Visitors on wider screens (e.g. 1750px) then receive a srcset whose largest 1x entry is 1440px, causing visible blur.
Root Cause
In _generateResponsiveSizes(), the condition was capping against currentWidth (CSS-rendered size) instead of naturalWidth (actual image pixel width).
Fix
Changed the condition to cap against naturalWidth instead, ensuring 1x srcset variants are generated for all breakpoints up to the image's actual pixel width.
Files Changed