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

Match the format to the image

Format choice is a trade-off among visual fidelity, file size, transparency, animation, encoding time, software support, and whether the file will be edited again. Judge candidate outputs at the dimensions and background where people will actually see them.

• JPG is a practical compatibility choice for photographs and other continuous-tone images, but it is lossy and has no alpha transparency.
• PNG is lossless and supports alpha transparency, making it useful for interface captures, diagrams, and graphics with sharp edges.
• WebP supports lossy and lossless coding, transparency, and animation, and is a flexible delivery format for modern web projects.
• AVIF supports efficient lossy and lossless coding plus features such as transparency and high bit depth, but encoding and workflow support should be tested.

Use source and delivery formats differently

A delivery asset is optimised for a particular channel; a source asset should retain what future edits need. Repeatedly opening and saving a lossy delivery file is a poor archival workflow. Keep a high-quality original or editable project, then generate JPG, WebP, or AVIF derivatives from it.

For logos and simple illustrations, SVG may be better than all four raster formats when a trustworthy vector source exists. For camera originals and print production, the best master may instead be a raw, TIFF, PSD, or another format outside this comparison.

• Archive the best available source rather than the smallest web derivative.
• Do not convert a small JPG to PNG expecting lost detail to return.
• Test colour profiles, transparency, and metadata because support varies by encoder and destination.

Deliver modern formats with a fallback

For websites, the HTML picture element can list AVIF and WebP sources while retaining an img fallback. The browser selects the first type it supports. Responsive srcset and sizes attributes solve a separate problem: they let the browser choose suitable pixel dimensions for the layout.

Do not create extra formats blindly. Each derivative adds build time, storage, cache variants, and testing. Measure representative images and keep only variants that produce a worthwhile result in the browsers and channels you support.

• Put newer preferred sources before fallback sources in a picture element.
• Always provide useful alternative text on the img element.
• Set intrinsic width and height to reserve layout space.
• Check email clients, social crawlers, content-management systems, and download workflows separately from browsers.

A practical decision order

First ask whether transparency, animation, lossless pixels, or very broad compatibility is mandatory. Then compare visual quality and byte size using real assets. Finally, verify decoding, colour, metadata, and operational cost in the target environment.

• Photo for broad distribution: start with JPG; add WebP or AVIF for controlled web delivery.
• Screenshot or diagram with crisp text: start with PNG, then compare lossless WebP or AVIF if supported.
• Transparent web graphic: compare PNG, WebP, and AVIF against the real page background.
• Animated content: consider video before animated image formats when the destination allows it.