PNG vs JPG vs WebP: Image Formats Explained

By SwiftPDF Team · Updated 2026-08-22 · 3 min read

Every image format is a trade-off between quality, size and features — and picking wrong costs you either blurry images or bloated pages. The format wars have also evolved: WebP and AVIF have joined the old PNG/JPG duopoly, and each has a job it's best at.

This guide gives you the mental model: what lossy and lossless mean, which formats support transparency, and a simple decision rule for every image you'll ever save.

The two big ideas: lossy vs lossless

Lossless formats (PNG, GIF) preserve every pixel exactly — what you save is what you get, forever, through unlimited re-saves. Lossy formats (JPG, WebP, AVIF) discard detail your eyes barely notice to achieve dramatically smaller files. The art is discarding only what nobody will miss.

Second idea: raster vs vector. Raster formats (everything above) store pixels; vector formats (SVG) store shapes as math, scaling infinitely. Logos and icons belong in SVG whenever possible.

PNG: the lossless workhorse

PNG preserves pixels perfectly and supports full transparency, making it ideal for logos, screenshots, UI graphics, text-heavy images and anything you'll edit again. Its weakness is photos: a photographic PNG can be 5–10x larger than an equivalent JPG with no visible benefit.

JPG: the photographic standard

JPG's lossy compression is tuned for photos and complex gradients, producing tiny files at quality settings around 80–85% that look identical to the source. It has no transparency support and smudges sharp edges and text — never use it for logos, screenshots of UI, or images you'll re-edit repeatedly.

WebP: the modern all-rounder

WebP does nearly everything: lossy compression ~25–35% smaller than JPG at equal quality, lossless mode rivaling PNG, transparency, and even animation. Browser support is now effectively universal. For web images, WebP is the default right answer in 2026 — with JPG/PNG as fallbacks only when you must support ancient software.

The rest of the family

• GIF: 256 colors, lossless, animation support — legacy for animation, still fine for tiny simple graphics
• AVIF: even smaller than WebP with superb quality, but slower to encode and patchier software support
• SVG: vector — perfect for logos, icons and illustrations; infinitely scalable, tiny files
• BMP/TIFF: uncompressed or archival — huge files; convert to PNG for everyday use

The decision rule

• Photo for web → WebP (or JPG for maximum compatibility) at 80–85% quality
• Logo, icon, screenshot, graphic with text → PNG (or SVG if it's vector art)
• Needs transparency + small size → WebP or PNG
• Animation → WebP or GIF
• Master file you'll edit → PNG or TIFF, never JPG

What about HEIC/HEIF?

HEIC is the format iPhones use for photos — superb compression, roughly half the size of JPG at equal quality. The catch is compatibility: Windows and many web workflows still stumble on it. Treat HEIC as a capture and storage format, not a sharing format.

When an iPhone photo needs to go anywhere — email, web upload, a Windows-using colleague — convert to JPG or WebP first. iOS can do this on share ('Most Compatible' setting), and free converters handle HEIC uploads the same way.

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