PNG vs WebP vs AVIF: Which Image Format Should You Use in 2026?

Choosing the wrong image format for your website can silently cost you page speed, SEO rankings, and storage costs. PNG, WebP, and AVIF all have legitimate uses — the trick is knowing which format wins in each situation. This guide breaks down the differences with real numbers so you can make the right call every time.

A quick history of web image formats

JPEG and PNG dominated the web for two decades. JPEG (1992) was designed for photographs and uses lossy compression to achieve small file sizes. PNG (1996) was created as an open alternative to GIF, offering lossless compression and alpha transparency. Both formats still work everywhere, but neither was designed for the modern web.

Google introduced WebP in 2010 specifically to improve web performance. It offers both lossy and lossless compression modes, transparency, and animation — all at file sizes around 25–35% smaller than their JPEG or PNG equivalents. By 2023, all major browsers supported WebP. AVIF is the newest format, offering even smaller files, but with some trade-offs around encoding speed.

Format comparison: PNG vs JPEG vs WebP vs AVIF

When to use PNG

PNG is the right choice when you cannot afford any quality loss and need transparency. Specific use cases:

• Logos and brand assets — A PNG with a transparent background is universally compatible and looks crisp at any size on any background colour.
• Screenshots and screen recordings — Text in screenshots develops visible JPEG artefacts around letters. PNG preserves the sharp edges that make text readable.
• Illustrations and icons — Graphics with large flat-colour regions (like SVG-equivalent illustrations) compress well with PNG's lossless algorithm.
• Source files — Always archive the original in PNG or TIFF before converting to a lossy format. Each re-save in JPEG degrades quality.

When to use WebP

WebP should be your default format for the web in 2026. It covers every use case JPEG and PNG cover, at smaller file sizes, with full browser support. Use WebP for:

• Hero images, banners, and background images on websites
• Product photos in e-commerce stores
• Blog post images and thumbnails
• Any image that previously would have been a JPEG
• Transparent images where you want smaller files than PNG

Convert your existing JPEG and PNG images using the Image Format Converter — it converts to WebP in seconds, right in your browser.

When to use AVIF

AVIF achieves the smallest file sizes of any common web format and produces noticeably better quality at high compression levels compared to WebP. However, it has two practical drawbacks: encoding is much slower (though this is only relevant at generation time, not for viewers), and a small fraction of older browsers do not support it. Use AVIF when:

• You are building a modern web app or progressive web app where you control the stack and can serve WebP as a fallback.
• You are optimising a high-traffic site and every kilobyte of image savings matters.
• You have large photographic images where AVIF's better handling of smooth gradients and skin tones provides visible improvements at the same file size.

The safest implementation serves AVIF with a WebP or JPEG fallback using the HTML <picture> element.

How to convert between formats

Converting is straightforward with the right tool. The ToolsGravity Image Format Converter handles all these conversions without quality loss beyond what the target format inherently requires:

• PNG → WebP (great for reducing logo/icon file sizes)
• JPEG → WebP (standard modernisation for existing photo libraries)
• PNG / JPEG → AVIF (for cutting-edge performance)
• WebP → PNG (when a tool or platform requires PNG)

Summary

In 2026, WebP is the sensible default for virtually all web images — it combines the benefits of JPEG (small photos) and PNG (transparency) in one format that every modern browser understands. Switch to AVIF where you need maximum compression and can provide fallbacks. Keep PNG for logos, screenshots, and source files. JPEG is still valid for maximum compatibility in contexts where you cannot guarantee WebP support.