Image Format Checker
Score whether photos ship as WebP or AVIF so phones do not download a JPEG/PNG hero — not a ranking trick.
What this tool gives you
Check image formats
Fetch a public page or paste HTML. The checker scores WebP/AVIF vs JPEG/PNG/GIF — not a ranking trick.
What this checker looks for
JPEG and PNG still work. WebP and AVIF usually cut 30–50% off hero bytes without visible quality loss.
WebP or AVIF present
Serve at least one modern raster format on public pages.
Coverage
Most raster URLs should be .webp/.avif, not leftover JPEG heroes.
Heavy formats
GIF, BMP and TIFF are the worst default for content photos.
Picture fallback
type="image/webp" plus a JPEG <img> covers old Safari.
SVG is fine
Icons and logos can stay SVG. This score cares about photos.
Not a ranking lever
This is bandwidth hygiene, not a citation trick.
How to use the checker
Fix alt and dimensions first, then format, then srcset, then loading hints.
Check the live page
Fetch the public URL or paste the HTML from view-source.
Encode heroes as WebP
Aim for 50–150 KB public images. AVIF is extra, not required.
Keep a JPEG fallback
Use <picture> when you still need a JPEG src for older browsers.
What healthy formats usually include
WebP for photos. AVIF optional. JPEG only as fallback. SVG for icons. No GIF heroes.
| Part | Job | Default for public sites |
|---|---|---|
| WebP | Default raster photo | 50–150 KB public heroes |
| AVIF | Smaller next-gen option | Offer first in <picture> |
| JPEG | Fallback only | Keep as <img src> beside WebP |
| PNG | Transparency / UI | Prefer WebP unless you need lossless UI |
| SVG | Icons and logos | Keep vector, do not rasterize |
| Never | GIF/BMP/TIFF photos | Replace content GIFs with WebP or video |
Related GEO pages
Fix alt, then width/height, then format, then srcset.
Image Srcset Checker
Score srcset, sizes, width descriptors and src fallback.
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.
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 format FAQs
Does WebP help ChatGPT cite my page?
No. Modern formats save bytes and LCP. Citations still depend on crawl access, answer-ready content and corroboration.
Is JPEG still OK as a fallback?
Yes. Put AVIF then WebP in <picture> and keep a JPEG <img src> for older browsers. Do not ship only a 2 MB PNG hero.
Should every icon be WebP?
No. SVG is better for logos and icons. This checker scores raster photos, not vector marks.