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

The table below is a practical starting point rather than an absolute ranking. File size depends heavily on the image itself, encoder settings and whether you use lossy or lossless modes.

JPEG is a lossy format designed around photographic content. It is supported almost everywhere, opens quickly in common software and can produce relatively small files for photos with complex color and texture. For email attachments, conventional websites, office documents and broad compatibility, JPEG remains a safe choice.

Its main limitations are that it does not support transparency and it is not ideal for graphics with hard text edges or repeated editing. Strong JPEG compression can create block artifacts, halos and smearing around high-contrast details. Saving the same JPEG repeatedly can compound those losses.

PNG is commonly used for screenshots, interface graphics, diagrams, logos and other images where exact pixel edges matter. It supports transparency and uses lossless compression, which makes it useful when you need to preserve crisp text or keep an alpha channel for compositing.

The tradeoff is file size. A full-resolution photograph saved as PNG can be much larger than the same photograph saved as JPEG, WebP or AVIF. PNG is therefore not automatically a higher-quality choice; it is simply a different tool optimized for different content.

WebP can handle both lossy and lossless compression and can preserve transparency. That flexibility makes it useful for many web workflows because the same format family can cover photographs, transparent graphics and smaller delivery assets.

For a new website where modern browser support is expected, WebP is often a practical compromise between size, visual quality and implementation simplicity. It is also widely supported by current image tools, although some older desktop workflows may still prefer JPEG or PNG.

AVIF is designed for high compression efficiency and can produce impressively small files for many images. It supports transparency and can be especially useful when page weight matters and the target environment supports the format.

The downside is that AVIF encoding and decoding can be more computationally intensive. In a browser-based tool, converting a large image to or from AVIF may therefore take noticeably longer than a simple JPEG or PNG operation. Compatibility is also worth checking when the file will be used in older software rather than only on the web.

You usually do not need to benchmark every format. Start by asking what type of image you have and what the receiving system expects.

Changing formats can change file size because the new format uses a different encoder, but conversion alone does not guarantee a smaller file. A JPEG converted to PNG may grow dramatically. A PNG photo converted to WebP may shrink. The result depends on both content and settings.

If your real goal is a file-size limit, use a compressor after choosing the appropriate format. If your goal is compatibility or transparency, use the converter and judge size as a secondary factor.