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

The number of image format choices has multiplied over the past decade. JPEG was the only answer for photos; now you're choosing between JPEG, PNG, WebP, AVIF, and sometimes GIF, SVG, or HEIC. The choice actually matters — the wrong format can make your images 3–4x larger than necessary or cause quality issues that can't be fixed.

The Quick Decision Guide

• Photograph or realistic image → WebP (or JPEG if WebP isn't supported in your context)
• Logo, icon, or graphic with hard edges → SVG (if vector) or PNG (if raster)
• Screenshot of software or text-heavy UI → PNG (text rendering is better) or WebP
• Transparent background needed → WebP or PNG (JPEG doesn't support transparency)
• Animation → GIF for simple, short animations; video (MP4/WebM) for complex
• Highest quality archiving → PNG or TIFF (lossless, no quality loss over saves)

JPEG: Still Worth Using

JPEG gets dismissed as 'old' but for situations where WebP support isn't guaranteed — email attachments, some CMS systems, printing services — JPEG remains the reliable default for photos. At quality 80-85 in most encoders, the quality loss is minimal and file sizes are 60-80% smaller than maximum quality.

PNG: Right for the Right Content

PNGs are massive for photos (a 6MB PNG vs a 500KB JPEG of the same image is common) but they're the correct choice for anything with text, sharp edges, or transparency. A screenshot of a website with text will look noticeably sharper as PNG than JPEG, because JPEG's compression creates visible artifacts around high-contrast edges.

WebP: The Current Best Default

WebP handles both photograph-style and graphic-style images better than JPEG or PNG respectively. Support is at 97%+ across modern browsers. File sizes are consistently 25-35% smaller than comparable JPEG at equivalent quality. If you're building a website today with no legacy constraints, WebP is the right default choice for non-SVG images.

The File Size Reality Check

Numbers from actual tests on a 3000x2000px photograph:

• PNG (lossless): 12.4MB
• JPEG (quality 85): 1.8MB
• WebP (quality 80, equivalent quality to JPEG 85): 1.2MB
• AVIF (quality equivalent): 0.9MB

The WebP advantage over JPEG is real but not dramatic for a single image. Where it becomes significant is a website with 50-100 images — the cumulative bandwidth saving meaningfully affects page load times.