How do I choose lossy vs lossless compression for web images?

A good rule of thumb:

• Use lossless when you need exact fidelity or the image is mostly sharp edges/text.
• Use lossy when you want much smaller files and can tolerate tiny visual changes.

Quick choice guide

Choose lossless for:

• Logos
• Icons
• UI graphics
• Screenshots with text
• Illustrations with flat colors
• Images where pixel-perfect detail matters

Why: lossless keeps every pixel exactly, so no blurring, banding, or artifacts.

Common formats:

• PNG (very common)
• WebP lossless
• AVIF lossless (supported in modern browsers)

Choose lossy for:

• Photos
• Background images
• Large hero images
• Any image where smaller file size matters more than exact pixel data

Why: lossy removes information the eye is less likely to notice, often shrinking files dramatically.

Common formats:

• JPEG/JPG
• WebP lossy
• AVIF lossy

Practical decision rules

If it’s a photo:

Use lossy almost always.

Typical best options:

• AVIF for best compression
• WebP for broad support and strong compression
• JPEG if you need maximum compatibility or faster encoding workflows

If it’s a graphic, logo, or screenshot:

Use lossless unless you can visually verify lossy is still acceptable.

Typical best options:

• PNG if compatibility matters
• WebP lossless or AVIF lossless if you want smaller files

A simple test

If you can answer “yes” to any of these, lean lossless:

• Will users zoom in on it?
• Does it contain text or sharp UI edges?
• Would a tiny blur or artifact look bad?
• Is it a logo or brand asset?

If “no,” lossy is probably fine.

Web performance tip

For modern websites, the best choice is often:

• Use AVIF/WebP
• Prefer lossy for photos
• Prefer lossless for sharp graphics
• Offer fallback formats if needed

Recommended defaults

• Photo: AVIF lossy → WebP lossy → JPEG fallback
• Logo/icon: SVG if possible; otherwise PNG/WebP lossless
• Screenshot: PNG or WebP lossless
• Illustration: test both; often WebP lossless or high-quality lossy

Bottom line

• Lossless = accuracy
• Lossy = smaller files
• Pick based on whether the image is photo-like or graphic/text-like

If you want, I can also give you a format-by-format cheat sheet for PNG vs JPEG vs WebP vs AVIF vs SVG.