WebP vs PNG vs JPEG: When to Use Each Format

Choosing the right image format can mean the difference between a lightning-fast website and one that frustrates users with slow load times. This guide breaks down when to use JPEG, PNG, WebP, and other formats to get the best balance of quality and performance.

The Quick Answer

If you're in a hurry, here's the cheat sheet:

Now let's dive deeper into each format to understand why.

JPEG: The Photography Standard

JPEG (Joint Photographic Experts Group) has been the web's go-to format for photographs since the 1990s. It uses lossy compression, meaning it permanently discards some image data to achieve smaller file sizes.

JPEG Pros

• • Universal support: Works everywhere, on every browser and device
• • Excellent for photos: Compression algorithm is optimized for photographic content
• • Adjustable quality: You can fine-tune the quality/size tradeoff
• • Small file sizes: Can achieve 10:1 compression with minimal visible loss

JPEG Cons

• • No transparency: Cannot have transparent backgrounds
• • Lossy compression: Quality degrades with each re-save
• • Poor for text/graphics: Creates visible artifacts around sharp edges
• • No animation: Static images only

PNG: The Transparency Champion

PNG (Portable Network Graphics) uses lossless compression, preserving every pixel exactly as intended. This makes it ideal when quality is paramount or when you need transparency.

PNG Pros

• • Transparency support: Full alpha channel for smooth transparency
• • Lossless quality: No degradation, perfect pixel reproduction
• • Sharp edges: Ideal for text, logos, and graphics
• • Universal support: Works in all browsers

PNG Cons

• • Large file sizes: Often 5-10x larger than JPEG for photos
• • Overkill for photos: Lossless compression isn't needed for most photographs
• • No animation: APNG exists but has limited support

WebP: The Modern All-Rounder

Developed by Google, WebP combines the best features of JPEG and PNG while delivering significantly smaller file sizes. It supports both lossy and lossless compression, transparency, and even animation.

WebP Pros

• • 25-35% smaller than JPEG: Same quality, much smaller files
• • 26% smaller than PNG: For lossless images with transparency
• • Supports transparency: Unlike JPEG
• • Supports animation: Smaller than GIF
• • Both lossy and lossless: Choose based on your needs

WebP Cons

• • Browser support: Now universal, but older browsers may need fallbacks
• • Software support: Some older image editors don't support it

AVIF: The Next Generation

AVIF (AV1 Image File Format) is the newest format, offering even better compression than WebP. It can be 50% smaller than JPEG while maintaining similar quality.

AVIF Pros

• • Best compression: 50% smaller than JPEG, 20% smaller than WebP
• • High quality: Excellent at low bitrates
• • Full feature set: Transparency, animation, HDR support

AVIF Cons

• • Browser support: ~93% support, but gaps remain
• • Encoding speed: Slower to compress than other formats
• • Limited tool support: Not all software supports it yet

SVG: For Vectors Only

SVG (Scalable Vector Graphics) is fundamentally different—it's not a pixel format at all. Instead, it describes images mathematically, allowing them to scale to any size without quality loss.

• • Infinitely scalable: Perfect at any resolution
• • Tiny file sizes: For simple graphics, often under 1KB
• • Editable with CSS/JS: Can be styled and animated
• • Not for photos: Only works for vector-based graphics

File Size Comparison

Here's a real-world comparison of the same 1920x1080 photograph saved in different formats:

Recommended Strategy

For most websites in 2025, here's what we recommend:

Using the Picture Element

The HTML <picture> element lets you serve different formats to different browsers:

<picture>
  <source srcset="image.avif" type="image/avif">
  <source srcset="image.webp" type="image/webp">
  <img src="image.jpg" alt="Description">
</picture>

The browser will use the first format it supports, falling back to JPEG for older browsers.

Conclusion

The image format you choose has a real impact on your website's performance. While JPEG and PNG have served us well for decades, modern formats like WebP offer meaningful improvements with broad browser support.

The key takeaway: don't overthink it. Use WebP for most images, SVG for vectors, and let tools like imgBoost handle the optimization. The most important thing is that you're compressing your images—that alone will make your site faster.