JPG vs PNG vs WebP vs AVIF: How to Choose

The essential differences

A file extension does not determine quality on its own. Encoder settings and image content matter just as much. A JPEG saved at an excessively low quality can show more blocking and banding than a sensibly encoded WebP or AVIF; a simple icon saved as high-quality JPEG can be both larger and softer than PNG.

Choose for the content, not for fashion

• Camera photos: JPEG is the compatibility baseline. WebP often reduces size further at a similar visual quality. AVIF makes sense when a modern-site fallback is available.
• Product screenshots: small text and straight edges expose lossy artifacts, so begin with PNG and test lossless WebP if size is high.
• Transparent icons: PNG is a safe default. WebP and AVIF preserve alpha too, but the rest of the workflow must support them.
• Archival masters: do not keep only a lossy export. Preserve the RAW, TIFF, or high-quality master and create delivery versions separately.

How to test the formats in tinysqueeze

1. Choose three representative files: a portrait, a detailed landscape, and an interface image with text or transparency.
2. Keep the same dimensions and export JPEG, WebP, and AVIF. Include PNG only where lossless output makes sense.
3. Inspect hair, text edges, sky gradients, and shadows at 100% zoom.
4. Compare file size and destination compatibility, then choose the batch output.

Do not judge only by thumbnails. Compression defects often hide in dark areas, gentle gradients, and sharp high-contrast edges. Smart auto searches for a lower JPEG/WebP/AVIF quality that still reaches its SSIM target, but a human should make the final call for important work.

A robust format stack for websites

A modern site can use the <picture> element to offer AVIF, WebP, and a JPEG/PNG fallback in that order. The browser picks the first source it can decode. If a CMS or build process cannot maintain multiple variants, WebP with a conventional fallback is often the simplest place to start.

When conversion changes URLs, update HTML references, caches, and relevant image records. Avoid replacing an entire historical library only because a format is newer; begin with the largest assets on the most visited pages and measure the result.