Image Compression Guide: JPEG vs PNG vs WebP vs AVIF

Choosing the right image format can reduce your file size by 50-90% without visible quality loss. This guide explains when to use each format and how to compress images effectively.

Quick Decision Chart

• Photo with no transparency? → JPEG (or WebP for 30% smaller)
• Image with transparency? → PNG (or WebP for smaller with transparency)
• Web use, modern browsers? → WebP (best size-to-quality ratio)
• Maximum compression, bleeding edge? → AVIF (50% smaller than JPEG)
• Logo, icon, illustration? → SVG (vector, scales to any size)
• Screenshot of text? → PNG (lossless preserves sharp text edges)

Format Comparison

JPEG — The Universal Photo Format

JPEG uses lossy compression that discards details the human eye can barely perceive. At quality 80-85%, most photos look identical to the original while being 10-20x smaller than raw image data.

When to use: Photographs, complex images with gradients, any image without transparency.

When NOT to use: Text, screenshots, logos, images needing transparency.

Tip: Quality 75-85% is the sweet spot. Below 60%, artifacts become visible.

PNG — Lossless Quality, Larger Files

PNG uses lossless compression — no quality is lost, ever. This makes it perfect for images with text, sharp edges, and transparency. The trade-off is larger file sizes compared to JPEG.

When to use: Screenshots, images with text, logos on transparent backgrounds, UI elements.

Optimization tip: PNG-8 (256 colors) is much smaller than PNG-24 (millions of colors). If your image has few colors (icons, simple graphics), PNG-8 can be 80% smaller.

WebP — The Modern Standard

Developed by Google, WebP offers 25-35% smaller files than JPEG at equivalent quality, and it supports transparency (unlike JPEG). It's now supported by 97% of browsers.

When to use: All web images. It's the best all-around format for websites.

Tip: If your image would be JPEG, convert to WebP for free size savings. If it would be PNG with transparency, WebP with lossless mode is usually smaller.

AVIF — Maximum Compression (Newer)

AVIF is the newest format, offering 50% smaller files than JPEG and 20% smaller than WebP. It's based on the AV1 video codec. Browser support is now at 92% (Chrome, Firefox, Safari 16+, Edge).

When to use: When you need maximum compression and can accept slightly slower encoding. Great for large image galleries and bandwidth-sensitive applications.

Limitation: Encoding is slower than JPEG/WebP. Some older browsers don't support it.

SVG — Scalable Vector Graphics

SVG is fundamentally different — it's code (XML) that describes shapes, not pixels. This means it scales to any size without quality loss and is often tiny in file size for simple graphics.

When to use: Logos, icons, illustrations, charts, anything that's not a photograph.

Optimization: Tools like SVGO can reduce SVG file size by 40-60% by removing unnecessary metadata, comments, and simplifying paths. Our Image Compressor includes SVGO optimization.

HEIC — iPhone's Default Format

HEIC (High Efficiency Image Container) is Apple's default photo format since iPhone 7. It's ~50% smaller than JPEG but not widely supported outside Apple devices.

Problem: Windows, Android, and most websites can't open HEIC files directly.

Solution: Convert HEIC to JPEG or WebP using our Image Compressor — it decodes HEIC locally in your browser.

How to Compress Images on FixMyFile

1. Go to Image Compressor
2. Drop your images (supports all formats above, plus ZIP batches)
3. Adjust quality slider (lower = smaller, higher = better)
4. Optionally convert to a different format (e.g., PNG → WebP)
5. Click Compress — compare before/after with the slider
6. Download all as ZIP

Key Takeaways

• For photos: use WebP (or JPEG for maximum compatibility)
• For transparency: use WebP or PNG
• For maximum compression: use AVIF
• For vectors/logos: use SVG
• Quality 75-85% is the sweet spot for lossy formats
• Always compress images before uploading to websites — page speed directly affects SEO ranking