Solution
Optimize images for Core Web Vitals without cloud uploads
Images are the largest contributor to Largest Contentful Paint (LCP) — the most impactful Core Web Vitals metric. Reducing image file size and using modern formats (WebP, AVIF) is the most effective single optimization for most pages.
ConV converts JPEG and PNG images to WebP or AVIF in your browser, typically achieving 25–50% smaller files. Smaller files load faster, improving LCP and overall page speed.
Batch process your hero images, product photos, and blog assets in one session — export as ZIP and deploy.
Key benefits
- 25–50% smaller files vs JPEG with WebP/AVIF output
- Directly improves Largest Contentful Paint (LCP)
- Batch convert all images for a page or site section
- ZIP export for fast deployment
Common use cases
- Frontend developers improving PageSpeed Insights scores
- SEO teams optimizing images for organic ranking
- E-commerce teams improving conversion rate via faster product pages
- Performance engineers addressing LCP for marketing landing pages
How it works
- 01
Identify large images from PageSpeed Insights or GTmetrix
- 02
Drop them into ConV
- 03
Convert to WebP or AVIF at quality 80–85
- 04
Replace originals with optimized files
Limitations and realistic expectations
ConV reduces image file size — improving LCP requires also serving images at the correct display size and using responsive srcset attributes. ConV does not implement these in your codebase.
Frequently asked questions
What Core Web Vitals does image optimization affect?
Primarily LCP (Largest Contentful Paint). Proper sizing also avoids layout shift (CLS). Image optimization is the highest-leverage improvement for most web pages.
How much can WebP improve LCP?
For typical web photos, WebP achieves 25–35% smaller files than JPEG at equivalent quality. Smaller files load faster, directly reducing LCP.
Should I use WebP or AVIF for Core Web Vitals?
AVIF achieves better compression but takes longer to encode and has slightly less legacy browser support. WebP is a safe default with broad support.
Does ConV upload images to optimize them?
No. All processing is local. This makes it safe for pre-launch site optimization where images may not be public yet.
Related solutions
Convert images to WebP without uploading them
WebP is the de-facto standard for web images. Converting to it typically reduces file size by 25–35% compared to JPEG, improving page speed and Core Web Vitals without loss of quality.
Convert images to AVIF locally in your browser
AVIF is the next-generation image format backed by the Alliance for Open Media. It achieves 30–50% better compression than JPEG at comparable visual quality and often outperforms WebP.
Optimize Shopify product images locally
Large product images slow Shopify stores and hurt Core Web Vitals scores. ConV lets you compress and convert product images to WebP or AVIF locally before uploading them to Shopify.