The Image Format Problem
You have a JPG. Someone tells you to use WebP. Then someone else says AVIF is better. Your designer sends a PNG. Your CMS wants everything in WebP. Your email client breaks if it's not JPG.
Let's settle this once and for all.
The Formats, Explained
JPEG (JPG) — The Old Reliable
Invented in 1992. Still the most-used image format on the web.
- Compression: good (lossy only)
- Transparency: no
- Browser support: 100%
- Best for: photographs, images with gradients, email, anything that needs universal compatibility
- Not for: images with text, logos, screenshots (compression artifacts appear)
Rule of thumb: when in doubt and compatibility matters, use JPG.
PNG — Lossless Quality With Transparency
- Compression: lossless (larger files than JPG for photos)
- Transparency: yes (alpha channel)
- Browser support: 100%
- Best for: logos, icons, screenshots, images with text, anything needing a transparent background
- Not for: photographs (files are 3–5× larger than equivalent JPG)
Rule of thumb: when you need transparency or pixel-perfect sharpness, use PNG.
WebP — Google's Upgrade to Both
Released by Google in 2010. Designed to replace both JPG and PNG.
- Compression: 25–35% smaller than JPG (same quality), 20–30% smaller than PNG
- Transparency: yes
- Animation: yes (replaces GIF)
- Browser support: 97%+ (all modern browsers — Chrome, Firefox, Safari 14+, Edge)
- Best for: web images where you control the browser environment
- Not for: email (many clients don't support it), apps targeting older devices
The catch: Safari only added WebP support in 2020. If you have users on iOS 13 or older Safari, you need a JPG fallback.
AVIF — The New Champion
Based on the AV1 video codec. Released around 2019, widely supported from 2022.
- Compression: 50% smaller than JPG at equivalent quality — the best available
- Transparency: yes
- Animation: yes
- Browser support: ~93% (Chrome, Firefox, Safari 16+, Edge — not IE, not old devices)
- Best for: web images where maximum compression matters, modern audiences
- Not for: tools that don't support it yet (Photoshop added support in 2023, some CMSs still don't)
The catch: encoding is slow (10–20× slower than WebP). For bulk conversion, use a tool.
GIF — Just Use WebP or Video
GIFs are 30 years old. They're 8-bit color, limited to 256 colors per frame, and comically oversized.
A 5 MB GIF can be a 300 KB WebP animation or a 200 KB MP4. There's almost no reason to use GIF in 2026 except for compatibility with platforms that specifically require it.
Format Comparison Table
| Format | File Size | Transparency | Animation | Support | Best For |
|---|---|---|---|---|---|
| JPG | Baseline | No | No | 100% | Photos, email |
| PNG | 3–5× JPG | Yes | No | 100% | Logos, screenshots |
| WebP | −30% JPG | Yes | Yes | 97% | Web photos & icons |
| AVIF | −50% JPG | Yes | Yes | 93% | Modern web, max compression |
| GIF | 10–20× WebP | Partial | Yes | 100% | Legacy compatibility only |
Which Format to Use: Decision Guide
For a photo on your website → AVIF (with WebP fallback for older browsers). Implementation in HTML:
<picture>
<source srcset="image.avif" type="image/avif">
<source srcset="image.webp" type="image/webp">
<img src="image.jpg" alt="...">
</picture>
For a logo with transparent background → WebP or PNG. WebP is 30% smaller; use PNG if you need 100% compatibility.
For email → JPG always. Email clients are a mess; JPG is the only safe format.
For a product page with many images → AVIF. The compression difference (50% vs JPG) has a real impact on page load time and Core Web Vitals.
For a GIF replacement on your site → WebP animation or MP4. Video to GIF creates WebP-compatible animations; most modern players handle MP4 loops cleanly.
For social media upload → JPG. Instagram, Twitter/X, Facebook all re-compress your image anyway.
The SEO Angle
Google's PageSpeed Insights and Core Web Vitals specifically penalize oversized images. Switching from JPG to WebP/AVIF on a website with 50+ images can move your LCP (Largest Contentful Paint) score significantly.
A JPG hero image at 400 KB = WebP at 280 KB = AVIF at 200 KB. The visual result is identical. The load time is not.
Convert Your Images Now
Image Converter converts between PNG, JPG, WebP, AVIF, and more — batch processing, free. No account required.
For compression without format change: Image Compressor reduces file size while preserving quality and format.