Image Srcset Checker
Score whether images ship srcset and sizes so phones do not download a 1600px file — not a ranking trick.
What this tool gives you
Check image srcset
Fetch a public page or paste HTML. The checker scores srcset, sizes and descriptors — not a ranking trick.
What this checker looks for
One file for every screen is waste. Srcset lets the browser pick 800w, 1200w or 1600w.
srcset present
Give the browser more than one candidate file.
w descriptors need sizes
800w without sizes is treated as 100vw.
Valid descriptors
Use 800w or 2x — not px or bare numbers.
src fallback
Keep src for browsers and crawlers that ignore srcset.
Picture is extra
<source srcset> helps, but the <img> still needs a fallback.
Not a ranking lever
This is bandwidth hygiene, not a citation trick.
How to use the checker
Fix alt and dimensions first, then srcset, then loading hints.
Check the live page
Fetch the public URL or paste the HTML from view-source.
Add width candidates
Ship 800w, 1200w and 1600w files instead of one oversized image.
Pair sizes with w
Width descriptors need sizes so the browser knows the layout slot.
What healthy srcset usually includes
Width candidates. sizes for w descriptors. Density 1x/2x when art is fixed. src fallback always.
| Part | Job | Default for public sites |
|---|---|---|
| srcset | Offer candidate files | 800w, 1200w, 1600w |
| sizes | Tell the layout slot | (max-width: 768px) 100vw, 1200px |
| w vs x | Pick one descriptor family | Do not mix 800w and 2x on the same srcset |
| src | Fallback file | src still present |
| picture | Art direction | source srcset plus img fallback |
| Never | One 2400px file for phones | Let srcset pick a smaller candidate |
Related GEO pages
Fix alt, then width/height, then srcset, then loading.
Image Format Checker
Score WebP/AVIF vs JPEG, PNG and GIF raster formats.
Image Loading Checker
Score eager LCP, lazy galleries, fetchpriority and decoding.
Image Dimension Checker
Score img width and height attributes so the layout does not jump.
Image Alt Checker
Score image alt coverage, useful descriptions, decorative empty alt and src.
H1 Checker
Score one visible h1, heading length, title overlap and outline order.
Favicon Checker
Score rel=icon href, type, sizes and apple-touch-icon tab-icon hygiene.
Viewport Meta Checker
Score width=device-width, initial-scale=1 and pinch-zoom hygiene.
Open Graph Checker
Score og:title, og:description, HTTPS og:image and matching og:url.
GEO Visibility Checklist
Score citation-ready content, entity clarity and weekly mention tracking.
Tools Lab
More generators, calculators and GEO workflows.
Image srcset FAQs
Does srcset help ChatGPT cite my page?
No. Srcset saves bandwidth and picks a file that matches the slot. Citations still depend on crawl access, answer-ready content and corroboration.
Do I need sizes if I use 1x and 2x?
No. Density descriptors do not use sizes. Width descriptors (800w) do — without sizes the browser assumes 100vw.
Is a <picture> source enough without img srcset?
Picture sources help art direction, but the <img> still needs a src fallback. This checker scores <img srcset> first.