AVIF vs GIF (and Everything In Between): Understanding Optimised Image Types for the Web

When it comes to building a fast, visually engaging website, choosing the right image format can make a huge difference. But with all the acronyms flying around — JPEG, PNG, WebP, AVIF, SVG, and even the old-school GIF — it can feel like you’re deciphering a secret code.

So, let’s break it down. Here’s your no-nonsense guide to the most common image types and when (and why) to use them.

1. GIF: The Internet’s Old Favourite (With Limitations)

Best for: Simple animations and memes
Avoid for: High-quality photos or anything where file size matters

The GIF (Graphics Interchange Format) has been around since the 1980s. It’s famous for simple animations, but it only supports 256 colours, doesn’t compress well, and creates bloated file sizes. Still useful in some cases, but there are better options now.

2. JPEG: The Classic Photo Format

Best for: Photographs, blog images, social media thumbnails
Avoid for: Images needing transparency or text overlays

JPEG (or JPG) uses lossy compression to reduce file size, which makes it fast-loading — but at the cost of quality. Good for images where you don’t need perfect detail, but not ideal for sharp graphics or logos.

3. PNG: The High-Quality Transparent Hero

Best for: Images with transparency, logos, icons
Avoid for: Large photos or galleries

PNG offers lossless compression, meaning it keeps all the detail, and supports transparency — perfect for overlaying logos and clean UI elements. But the trade-off? Bigger file sizes compared to JPEG or WebP.

4. WebP: The Best of Both Worlds (For Now)

Best for: General web use — from product images to blog headers
Avoid for: Some older browsers (though support is now very broad)

Created by Google, WebP supports both lossy and lossless compression, transparency, and even animation. It’s often 25–35% smaller than equivalent JPEG or PNG files, making it an excellent all-rounder. It’s supported in all major browsers now, so it’s a solid default.

5. AVIF: The New Generation Format

Best for: Next-level optimisation — especially for mobile and high-res screens
Avoid for: Projects needing wide compatibility or very fast server-side processing

AVIF (AV1 Image File Format) is the latest and greatest in image compression. It supports HDR, transparency, and stunning compression ratios — often beating WebP by 20–50%. But it’s slower to encode and decode, and not yet supported by every browser or CMS out-of-the-box. It’s your “future-proof” option.

6. SVG: The Infinite Scaler

Best for: Icons, logos, simple illustrations
Avoid for: Complex images or photos

SVG (Scalable Vector Graphics) isn’t a pixel-based format — it’s vector, meaning it scales infinitely without losing quality. Plus, it’s lightweight, editable with code, and incredibly useful for responsive design.

7. Lottie: Lightweight Animation with Interactivity

Best for: Animated icons, UI elements, onboarding flows
Avoid for: Complex video-style loops, email use, or no-JavaScript environments

Lottie is a JSON-based animation format developed by Airbnb. Instead of using image frames like GIFs or WebP, it uses vector data and instructions to render animations in real-time via JavaScript. This makes Lottie files tiny, resolution-independent, and interactive — perfect for web and mobile UIs.

It’s ideal for animated buttons, icons, logos, or micro-interactions in apps and websites. You’ll need a JavaScript player (like Lottie Web), but platforms like Webflow, Elementor, and Flutter already support Lottie natively.

TL;DR: Choosing the Right Image Type

Format	Best For	Compression	Transparency	Animation	Browser Support
GIF	Simple animations	Low	Yes	Yes	Excellent
JPEG	Photos	Lossy	No	No	Excellent
PNG	Logos, UI	Lossless	Yes	No	Excellent
WebP	All-round use	Lossy/Lossless	Yes	Yes	Very good
AVIF	High-performance web	Lossy/Lossless	Yes	Yes	Good (growing)
SVG	Icons, vectors	N/A (vector)	Yes	Limited	Excellent
Lottie	Animated UI, icons	Very small (vector)	Yes	Yes (JS-based)	Requires JS player

Final Thoughts

If you’re serious about website speed, accessibility, and SEO, then image optimisation matters. WebP is a fantastic go-to for now, with AVIF ready to take over as browser and CMS support continues to grow. Stick with PNG and SVG for logos and UI, Lottie for scalable animations, and only use GIFs if you really need a retro feel or simple loop.

Want help setting up automated image optimisation or Lottie integration on your site? Give us a shout — your PageSpeed score will thank you.