Modern Image Formats on Content
Checks content images use WebP or AVIF, not legacy JPEG/PNG for photos.
What this check measures
We fetch page images and analyze format. Photos served as JPEG are flagged if WebP would save ≥30%. PNG for photos (common AI-generation artifact) is flagged aggressively.
Why it matters
Every unnecessary KB hurts LCP on mobile. A page with 20 product photos as legacy JPEG can take 3-5s to load over 4G. WebP cuts that to 1-2s. AVIF (where supported) even better.
How our audit detects it
Fetch images, check Content-Type. Estimate WebP-conversion savings per image.
Typical findings
- error_outlineProduct page with 30 JPEG photos, 8MB total.
- error_outlineAI-generated PNGs for blog illustrations (5-10MB each).
How to fix
Convert photos to WebP (universal) or AVIF (smaller, needs <picture> fallback). Next.js Image component does this at request time automatically.
Copy-paste fix prompt for your stack
Lovable · Cursor · Bolt · v0 · Replit · Windsurf · Claude Code · Base44
Frequently asked questions
PNG vs WebP for logos?expand_more
Want this checked on your site?
Pantra runs the full audit (SEO, Security, GEO, Performance, Schema, Technical, Images) in 10 seconds and generates stack-specific fix prompts.
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