Images account for an average of 65% of an e-commerce page's weight. Lexiik fully automates their optimization: intelligent resizing, WebP/AVIF conversion, CDN delivery, and AI-powered ALT tag generation. Result: pages that are 3x faster with no loss of visual quality.
Availability
Why optimize images?
Unoptimized images are the leading cause of slow e-commerce websites. They directly impact:
- Search engine ranking (SEO): Google penalizes slow websites since 2021 (Core Web Vitals)
- Conversion rate: Each additional second of load time = -7% conversion (Google 2023 study)
- User experience: 53% of visitors abandon a site that takes more than 3 seconds to load
- Bounce rate: Heavy images = slow pages = visitors who leave immediately
- Accessibility: ALT tags allow visually impaired users to understand image content
Measurable business impact
An internal study conducted on 150 Lexiik stores between January and December 2025 shows:
| Metric | Before Lexiik | After Lexiik | Improvement |
|---|---|---|---|
| Average product page weight | 4.2 MB | 1.1 MB | -74% |
| Load time (LCP) | 5.8 seconds | 1.9 seconds | -67% |
| Bounce rate | 58% | 41% | -29% |
| Conversion rate | 1.8% | 2.4% | +33% |
| PageSpeed Insights score | 42/100 | 87/100 | +107% |
Recommendation
Intelligent and automatic resizing
Lexiik automatically resizes your images to optimal dimensions for each display context, without manual intervention. No more 4000x3000 pixel images displayed at 300x200 pixels!
Optimal dimensions by context
| Display type | Lexiik dimensions | Target weight |
|---|---|---|
| Thumbnail (product list) | 300x300 px (2x for Retina) | 15-30 KB |
| Product gallery (desktop) | 1200x1200 px | 80-150 KB |
| Product gallery (mobile) | 800x800 px | 40-80 KB |
| High-resolution zoom | 2400x2400 px (lazy loading) | 200-300 KB |
| Open Graph (social media) | 1200x630 px (ratio 1.91:1) | 50-100 KB |
Responsive images (srcset)
Lexiik automatically generates multiple versions of each image and uses the HTML srcset attribute to serve the right size for each device:
<img
src="https://cdn.lexiik.com/product-123_800w.webp"
srcset="
https://cdn.lexiik.com/product-123_300w.webp 300w,
https://cdn.lexiik.com/product-123_600w.webp 600w,
https://cdn.lexiik.com/product-123_800w.webp 800w,
https://cdn.lexiik.com/product-123_1200w.webp 1200w
"
sizes="(max-width: 640px) 100vw, (max-width: 1024px) 50vw, 33vw"
alt="40L waterproof black hiking backpack"
loading="lazy"
/>The browser automatically chooses the version suited to the screen size, saving up to 70% of bandwidth on mobile.
Lazy Loading
Compression and modern formats
WebP, AVIF, and JPEG: which format to choose?
Lexiik automatically converts your JPEG/PNG images to modern formats that are lighter and better quality. To learn more about the technical differences, see our WebP vs AVIF guide.
| Format | Weight savings | Browser support | Required plan |
|---|---|---|---|
| Optimized JPEG | Reference (100%) | 100% (universal fallback) | Free |
| WebP | -30% vs JPEG | 97% (Chrome, Firefox, Edge, Safari 14+) | Free |
| AVIF | -50% vs JPEG | 89% (Chrome 85+, Firefox 93+, Safari 16+) | Pro+ |
Automatic conversion pipeline
When you upload an image to your store, Lexiik automatically applies this pipeline:
- Source image analysis: Format, dimensions, weight, and quality detection
- Metadata cleanup: Removal of unnecessary EXIF data (geolocation, camera info, etc.)
- Intelligent resizing: Generation of 4-6 variants (300px, 600px, 800px, 1200px, 2400px)
- Adaptive compression: 85% quality for photos, 100% for logos/text
- Multi-format conversion: Generation of JPEG, WebP, and AVIF versions (if Pro+ plan)
- CDN upload: Distribution from Lexiik's 35 datacenters (if Pro+ plan)
- ALT tag generation: Computer vision analysis and AI-powered writing
Pipeline duration: 2-5 seconds per image. Processing happens in the background, you don't need to do anything.
AVIF Premium
CDN Edge Computing delivery
Once optimized, your images are delivered via the Lexiik CDN (Content Delivery Network), a network of 35 datacenters distributed worldwide. To learn more about how it works, see our dedicated CDN guide.
CDN advantages for images
- Reduced latency: The image is served from the datacenter closest to the visitor
- Bandwidth savings: Your server no longer needs to serve images (70% less traffic)
- Maximum availability: If a datacenter goes down, the CDN automatically redirects to another
- Smart caching: Popular images remain cached for 30 days
- On-the-fly transformation: Dynamic resizing via URL parameters
On-the-fly image transformation
The Lexiik CDN allows you to modify images directly via the URL, without storing new versions:
# Original image
https://cdn.lexiik.com/shop-123/product-456.jpg
# Resize to 400px wide (automatic height)
https://cdn.lexiik.com/shop-123/product-456.jpg?w=400
# Convert to WebP + 80% quality
https://cdn.lexiik.com/shop-123/product-456.jpg?format=webp&q=80
# Square crop 600x600 + AVIF format
https://cdn.lexiik.com/shop-123/product-456.jpg?w=600&h=600&fit=cover&format=avifThis feature is particularly useful for developers who want to adapt images without going through Lexiik.
Cache-Control
Cache-Control: max-age=2592000 (30 days). If you modify an image, change its filename to force cache refresh.Automatic AI-powered ALT tag generation
ALT tags (alternative text) are crucial for SEO and accessibility. Lexiik generates them automatically through image analysis via computer vision. To learn more, see our dedicated ALT tag guide.
Computer vision analysis
Lexiik's AI analyzes each image and detects:
- The main subject: Product, person, place, object
- Dominant colors: Black, red, multicolored, etc.
- The context: Indoor, outdoor, studio photo, lifestyle
- Technical characteristics: Material, texture, shape
- Emotions: Joyful, elegant, sporty, luxurious (semantic analysis)
Examples of generated ALT tags
| Product type | ALT tag generated by Lexiik |
|---|---|
| Hiking backpack | 40L waterproof black hiking backpack with ergonomic straps |
| Running shoes | Women's electric blue running shoes with cushioned sole |
| Desk lamp | Modern black metal LED desk lamp with articulated arm |
| Summer dress | Long summer dress with red floral pattern and thin cotton straps |
ALT tag customization
You can configure the writing style of ALT tags:
- Length: Short (5-8 words), Medium (10-15 words), Long (15-20 words)
- Tone: Descriptive, commercial, technical
- Priority keywords: Lexiik naturally integrates them into the description
- Language: French, English, German, Italian, Spanish, Portuguese, Polish
Manual validation recommended
Use cases and real scenarios
Scenario 1: Migrating a legacy catalog
You have 2,000 products with unoptimized images (5-8 MB photos uploaded directly from the camera):
- Initial import: Lexiik detects heavy images and automatically launches optimization
- Bulk processing: 2,000 images optimized in 30-45 minutes (parallelized across 8 workers)
- CDN switchover: Your product pages now point to cdn.lexiik.com
- ALT tag generation: 2,000 descriptions automatically generated
Result: Average page weight divided by 4, load time reduced by 70%, PageSpeed score went from 35 to 82.
Scenario 2: Multi-device optimization
Your mobile traffic represents 65% of your visitors, but your images are too heavy for 4G connections:
- Lexiik automatically generates mobile (800px) and desktop (1200px) versions
- The server detects the device type and serves the right version (via User-Agent or srcset)
- Mobile users download 60% less data
- Mobile bounce rate drops from 68% to 44%
Scenario 3: International store (Green SEO)
You sell in 15 countries. Serving images from a single server in France generates significant latency for visitors in the United States, Australia, or Japan:
- The Lexiik CDN (35 datacenters) automatically serves images from the nearest point
- Average latency: 20-40 ms (vs 300-800 ms without CDN)
- Reduced carbon footprint: less data transfer = fewer CO2 emissions (see our Green SEO guide)
Best practices and recommendations
Before uploading
- Consistent naming: Use descriptive names (e.g.:
hiking-backpack-black-40l.jpgrather thanIMG_1234.jpg) - Source format: Prefer JPEG for photos, PNG for logos/text (Lexiik will then convert to WebP/AVIF)
- Minimum resolution: 1200x1200 px minimum for optimal quality after resizing
- Aspect ratio: Prefer square format (1:1) for catalog uniformity
During optimization
- Monitor logs: If more than 5% of images fail, check source formats
- Test on mobile: Verify that responsive versions display correctly
- Validate ALT tags: Manually check 10% of generated descriptions
After optimization
- PageSpeed Insights test: Check score improvement (target: >80/100)
- Core Web Vitals monitoring: Track LCP (Largest Contentful Paint) evolution
- Google Images indexing: Submit your image sitemaps to Search Console
- A/B Testing: Compare conversion rates before/after optimization
Pro tip
ROI and performance gains
Calculating savings
For an e-commerce site with 500 products and 100,000 monthly visitors:
| Metric | Before Lexiik | After Lexiik |
|---|---|---|
| Monthly bandwidth | 12 TB | 3.2 TB (-73%) |
| Monthly hosting cost | 180€ | 65€ (-115€/month) |
| Conversion rate | 1.8% | 2.4% (+33%) |
| Additional monthly revenue (avg. cart 80€) | - | +4,800€ |
ROI Lexiik Pro Plan (59€/month):
- Hosting savings: 115€/month
- Additional revenue: 4,800€/month
- Lexiik cost: -59€/month
- Net profit: +4,856€/month (ROI of 8,130%)
SEO impact of optimized images
According to an internal study conducted on 200 Lexiik stores in 2025:
- +52% traffic from Google Images after 3 months of optimization
- +38% Top 10 rankings for transactional queries
- -41% bounce rate thanks to faster pages
- +27% pages per session (navigation facilitated by speed)
Ready to automatically optimize your images?
Image optimization is available on all plans, including the free plan. AVIF formats and the premium CDN are included from the Pro plan.
View plans →