Image Compression Basics and EXIF Privacy Guide (Client-Side Demo Tool)

Summary

A single unoptimized hero image can weigh more than your entire web-page budget. Welcome to your crash course on image compression. In the next 10 minutes you’ll learn: Why images slow sites down (and hurt SEO) Lossy vs. Lossless compression in plain English Key metrics—quality %, resolution, file size Popular formats (JPEG, PNG, WebP, AVIF) A step-by-step demo using SlimImg—no upload, privacy-safe 1. Why Should You Care? Performance – every extra 100 KB can add ≈ 0.3 s to Largest Contentful Paint. Mobile data cost – users on 4 G pay for each megabyte. SEO – Google’s Core Web Vitals ranking factors reward fast pages. Accessibility – slim pages load on older devices and poor connections. 🔍 Case study: An e-commerce store compressed all product photos, cut average page size by 68 % and lifted conversion rate by 38 %. 2. Lossy vs. Lossless Type How it works Typical saving When to use Lossless Removes metadata, optimizes entropy without dropping pixels 10–30 % UI icons, logos, graphics with text Lossy Discards detail the eye barely sees 40–90 % Photos, hero banners, backgrounds Pro tip: Combine both—first lossless, then gentle lossy. 3. Key Metrics Quality % (q-factor) – lower = smaller file, but more blur. Resolution – serving a 4 K image to a 1080 p viewport wastes pixels. File size – what users actually download. graph LR; A[Original 4 MB] -->|Lossless 20 %| B(3.2 MB); B -->|Resize ×2| C(0.8 MB); C -->|Lossy q=80| D(0.25 MB); Example pipeline turning a 4 MB DSLR shot into a 250 KB web-ready hero. 4. Popular Formats at a Glance Format Best for Browser support (2025) Typical saving vs JPEG JPEG/JPG Photos 100 % baseline PNG Transparency, UI 99 % 5–30 % (lossless) WebP Web photos + alpha 97 % 25–35 % AVIF Next-gen photos, HDR 92 % 30–50 % 5. Hands-On: Compress Your First Image with SlimImg 🕒 Time required: 2 minutes Open https://slimimg.tools Drag & drop your image (JPG / PNG / WebP / AVIF) Adjust the quality slider—preview updates instantly (Optional) Resize or strip E...