Image Compression Guide: WebP vs AVIF vs JPEG vs PNG

Images are usually the heaviest part of a web page. Picking the right format and quality can cut file size dramatically while keeping pictures sharp.

Lossy vs lossless

Lossy formats (JPEG, WebP, AVIF) drop detail your eyes barely notice, shrinking files a lot. Lossless (PNG) keeps every pixel — best for logos and transparency, but large for photos.

Which format to use

• Photos & thumbnails: WebP is the best default — 25–35% smaller than JPEG with wide support.
• Smallest size on modern browsers: AVIF.
• Maximum compatibility: JPEG.
• Logos, icons, transparency: PNG or lossless WebP.

Choosing a quality value

• WebP / JPEG: quality 70–80 balances size and clarity.
• AVIF: start around 50–60 for the same perceived quality.
• PNG has no quality slider — if it's large, it's probably a photo that belongs in WebP.

Lower the quality step by step and compare before/after — pick the value just before quality visibly drops.

In short

Use WebP at quality 75 for web photos, AVIF for the smallest files, and PNG for transparency. With Scrunch you can convert many images at once, right in your browser.