이미지 형식 설명: 2026년 JPG vs PNG vs WebP vs AVIF 사용 시기

Choosing the wrong image format costs you page speed, user experience, and bandwidth. Here’s a practical guide to the four major formats and when each makes sense.

JPEG (JPG) — Still the universal standard

Best for: Photographs, complex images with many colors.

JPEG uses lossy compression that works well for natural scenes. It’s supported everywhere. The downsides: no transparency, no animation, and visible artefacts at very low quality settings.

When to use it: Background photos, product images on e-commerce, hero banners. Basically any photograph where file size matters more than perfection.

PNG — For precision

Best for: Screenshots, logos, images with text, graphics with sharp edges.

PNG offers lossless compression with full transparency support. The tradeoff is file size — PNGs are typically 2-5x larger than JPEG for photographs.

When to use it: UI elements, logos, screenshots, infographics. Anything with text or sharp edges where JPEG artefacts would be noticeable.

WebP — The modern default

Best for: Replacing both JPEG and PNG in most cases.

WebP supports both lossy and lossless compression, plus transparency and animation. Lossy WebP is 25-35% smaller than JPEG at the same quality. Lossless WebP is 25-30% smaller than PNG.

When to use it: Everything new. Browser support is 97%+. Convert existing JPEGs and PNGs to WebP for immediate bandwidth savings.

AVIF — The next generation

Best for: Maximum compression, HDR images, wide color gamut.

AVIF is 50-60% smaller than JPEG at the same quality. It supports HDR, 10/12-bit color, and transparency. The tradeoff is slower encoding (2-3x slower than WebP).

When to use it: Hero images, large photos, and when every kilobyte matters. Browser support is at 91% and growing.

Quick decision guide

Use Case Best Format Why Photo on a website WebP or AVIF 25-60% smaller than JPEG Logo with transparency PNG or WebP Needs alpha channel Screenshot Lossless WebP Smaller than PNG, same quality Email attachment JPEG Universal compatibility E-commerce product photo WebP Best size-quality balance Social media image JPEG or PNG Platform re-encodes anyway GIF replacement WebP animated Smaller than GIF, better quality

The one tool you need

ToolBox Image lets you convert between all four formats instantly in your browser with no uploads. It also has target-size compression so you can set an exact file size limit. Free, no sign-up.