WebP vs JPEG vs PNG vs AVIF: Complete Image Format Comparison Guide (2025)

Choosing the right image format can make or break your website's performance. With modern formats like WebP and AVIF promising dramatically smaller file sizes, the old JPEG vs PNG debate has become far more complex. This guide breaks down everything you need to know to make the right choice for your specific use case.

The Quick Comparison: Which Format Should You Use?

Before diving deep, here's a practical decision framework:

Understanding Each Format

JPEG: The Universal Standard

JPEG (Joint Photographic Experts Group) has been the web's workhorse since 1992. It uses lossy compression, meaning it permanently discards some image data to achieve smaller file sizes.

Strengths:

• Universal browser and device support (100%)
• Excellent for photographs and complex images
• Adjustable quality levels (typically 60-85% is optimal)
• Supported everywhere: email clients, social media, legacy systems

Weaknesses:

• No transparency support
• Lossy compression causes artifacts, especially at low quality
• No animation support
• Larger files compared to modern formats

Best quality settings: 75-85% for web images balances quality and file size. Below 60%, compression artifacts become noticeable.

PNG: Lossless with Transparency

PNG (Portable Network Graphics) was created in 1996 as a patent-free alternative to GIF. It offers lossless compression, meaning no image data is lost.

Strengths:

• Lossless compression preserves every pixel
• Full alpha transparency (variable opacity)
• Perfect for logos, icons, and graphics with sharp edges
• Great for screenshots and text-heavy images

Weaknesses:

• Significantly larger file sizes than lossy formats
• Overkill for photographs
• No native animation (APNG exists but has limited support)

PNG-8 vs PNG-24: PNG-8 uses a 256-color palette (smaller files, good for simple graphics), while PNG-24 supports millions of colors (larger files, better for complex images).

WebP: The Modern Standard

Developed by Google in 2010, WebP was designed specifically for the web. It supports both lossy and lossless compression, plus transparency and animation.

Strengths:

• 25-35% smaller than JPEG at equivalent quality
• 26% smaller than PNG for lossless images
• Supports transparency (like PNG)
• Supports animation (replacing GIF)
• 96%+ browser support as of 2025

Weaknesses:

• Not supported in some legacy systems and older email clients
• Slightly slower encoding than JPEG
• Some image editing software still has limited support

AVIF: Maximum Compression

AVIF (AV1 Image File Format) is the newest contender, released in 2019. Based on the AV1 video codec, it offers the best compression ratios of any format.

Strengths:

• 50%+ smaller than JPEG at equivalent quality
• 20% smaller than WebP
• Excellent color depth (10-bit and 12-bit support)
• HDR and wide color gamut support
• Supports transparency and animation

Weaknesses:

• ~85% browser support (no Safari before 16.0, limited on older browsers)
• Slower encoding and decoding than WebP
• Relatively new—tooling still maturing

Head-to-Head Comparison

Browser Support (2025)

Implementing Multiple Formats: The Picture Element

The best approach for maximum performance and compatibility is serving different formats based on browser support:

<picture>
    <!-- AVIF for browsers that support it (best compression) -->
    <source srcset="image.avif" type="image/avif">

        <!-- WebP for browsers that support it -->
        <source srcset="image.webp" type="image/webp">

            <!-- JPEG fallback for everything else -->
            <img src="image.jpg" alt="Description" loading="lazy">
            </picture>

This approach ensures every visitor gets the smallest possible file their browser can handle.

Real-World Performance Impact

When to Use Each Format: Decision Flowchart

Start here: What type of image are you working with?

Photograph or complex image: → Does your audience use modern browsers? → WebP (with AVIF for cutting-edge optimization) → Need maximum compatibility (email, legacy systems)? → JPEG

Logo, icon, or graphic: → Need transparency? → WebP or PNG (PNG for maximum compatibility) → No transparency needed? → WebP or JPEG

Screenshot or text-heavy image: → PNG or WebP lossless (preserves sharp edges)

Animation: → WebP or AVIF (both vastly superior to GIF)

Converting Between Formats

Manual Conversion Tools

• Squoosh (squoosh.app): Google's free tool with real-time quality comparison
• ImageMagick: Command-line tool for batch processing
• Photoshop/GIMP: Export options for all major formats

Automated Conversion with VisionFly

Manual conversion works for small sites, but becomes impractical at scale. Every new image needs converting to multiple formats, and you need to maintain fallback logic.

https://img.visionfly.ai/your-image?w=800&f=auto

Key Takeaways

1. WebP should be your default for most web images in 2025—it's well-supported and offers significant savings over JPEG/PNG

2. AVIF is the future but requires fallbacks; use it alongside WebP for maximum compression

3. JPEG isn't dead—it's still the safest choice when you need universal compatibility

4. PNG is for specific use cases: lossless requirements, transparency with maximum compatibility, or images with sharp text

5. Automate format selection whenever possible—manually managing multiple formats doesn't scale