What is the best image format for a website?

For most sites in 2026, WebP is the practical default: 25–35% smaller than JPEG with broad support. Use AVIF for high-traffic pages where every kilobyte counts, and keep JPEG as a fallback for maximum compatibility.

Which image format has the smallest file size?

AVIF generally produces the smallest files — roughly 40–50% smaller than JPEG and 30% smaller than WebP at similar quality — at the cost of slower encoding.

When should I use PNG instead of JPG?

Use PNG for screenshots, logos, diagrams, text overlays, and anything needing a transparent background. Use JPG for photographs, where PNG files become 5–10× larger for no visible benefit.

Is WebP better than JPG?

For the web, usually yes — WebP is smaller at equivalent quality and supports transparency. JPG still wins where compatibility matters most, such as email attachments and some older apps.

JPG vs PNG vs WebP vs AVIF: Which Format Should You Use?

A practical comparison of the four main image formats for the web. Covers file size, quality, browser support, and when to use each format.

The four main web image formats

Choosing the right image format can cut your file sizes in half — or double them if you choose wrong. Here's a practical overview of when to use each format.

JPG (JPEG)

Best for: Photographs, complex scenes with lots of colour gradations.

Compression: Lossy. Permanently discards subtle colour data. Transparency: Not supported. Browser support: 100% — every browser and device. Typical file size: 2–5 MB for a 12 MP photo at 85% quality.

JPG has been the standard for photos since 1992. Its near-universal support makes it the safe default when you don't know what platform your image will be displayed on.

PNG

Best for: Screenshots, logos, illustrations, images with text, images with transparency.

Compression: Lossless. Every pixel is preserved exactly. Transparency: Supported (alpha channel). Browser support: 100%. Typical file size: 20–40 MB for a 12 MP photo (not suitable for photos).

Use PNG when pixel-perfect accuracy matters — for UI screenshots, graphic assets, or any image you'll be editing multiple times. Never use PNG for photographs on a website; the file sizes are far too large.

WebP

Best for: Web images where you want smaller files than JPG with wider format flexibility than PNG.

Compression: Both lossy and lossless modes available. Transparency: Supported. Browser support: All modern browsers (Chrome, Firefox, Safari 14+, Edge). No IE support. Typical file size: 25–35% smaller than JPG at equivalent visual quality.

WebP was created by Google and is now the recommended format for most web images. If your audience uses modern browsers, switching from JPG to WebP is a simple way to reduce page weight without any visual trade-off.

AVIF

Best for: High-quality images where maximum compression is critical — hero images, large product photos.

Compression: Lossy and lossless. Transparency: Supported. Browser support: Chrome 85+, Firefox 93+, Safari 16+. Good but not universal. Typical file size: 40–50% smaller than JPG at equivalent quality.

AVIF offers the best compression of any mainstream format. The trade-off is slower encoding (our converter may take a few seconds for large files) and slightly lower browser support than WebP.

Quick decision guide

Photograph for the web → WebP (or JPG for maximum compatibility) Logo or icon with transparency → PNG (or WebP) Hero image on a modern website → AVIF Image shared via email → JPG Screenshot → PNG IPhone photo to share → JPG (converted from HEIC)