PNG vs JPG: Which Format Should You Use?

The fundamental difference

The core difference between PNG and JPG comes down to one concept: lossless vs lossy compression.

PNG (Portable Network Graphics) uses lossless compression. Every pixel is stored exactly as-is. When you save, re-save, or convert a PNG, the image data is never changed. This makes PNG the format of choice for images where pixel-perfect accuracy matters: logos, screenshots, UI mockups, icons, and design assets.

JPG (JPEG) uses lossy compression. It deliberately discards visual information the human eye is less likely to notice, particularly fine high-frequency details. This enables dramatically smaller file sizes — often 5–10× smaller than equivalent PNG files — at the cost of some image quality. Each time you save a JPG, quality decreases slightly (called "generation loss").

When to use PNG

• Logos and brand marks — especially those with transparent backgrounds
• Screenshots and screen recordings where text sharpness matters
• UI/UX mockups and design assets
• Images that will be edited and re-saved multiple times
• Images with large areas of flat color (illustrations, charts, diagrams)
• Any image requiring alpha transparency
• Favicons (as a source before converting to ICO)

When to use JPG

• Photographs — portraits, landscapes, product photos
• Images for social media sharing (Instagram, Facebook, Twitter)
• Email attachments where file size matters
• Web images that do not require transparency
• Images for print (most print shops accept JPG)
• Camera photos that do not need editing
• Any image where maximum compatibility is more important than pixel perfection

File size comparison

For a typical 1920×1080 photograph, you might expect:

• PNG: 2–5 MB (lossless)
• JPG at 92% quality: 300–600 KB
• JPG at 80% quality: 150–300 KB
• WebP at 92% quality: 200–400 KB

For a typical 500×500 logo with transparency:

• PNG: 20–80 KB (lossless, preserves transparency)
• JPG: 15–40 KB (but transparency becomes white, quality slightly reduced)
• SVG: 2–20 KB (if the logo is vector)

The transparency issue

This is one of the most important differences. PNG supports alpha transparency — meaning pixels can be fully transparent, fully opaque, or any degree of semi-transparency. This is essential for logos that need to be placed on different colored backgrounds, and for UI elements that overlay content.

JPG does not support transparency. If you save an image with a transparent background as JPG, the transparent areas are filled with a solid color (usually white). This makes JPG unsuitable for any image that needs to be composited over different backgrounds.

Quality degradation

JPG's lossy compression introduces compression artifacts — particularly visible as blocky patterns around sharp edges and text. At high quality settings (90%+), these artifacts are nearly invisible. At lower settings (below 70%), they become increasingly obvious.

PNG never has compression artifacts. The image is always exactly what you put in — no artifacts, no degradation, ever. This makes PNG the only viable choice for images with text, sharp lines, or fine detail that must be preserved perfectly.

Should you ever convert between the two?

PNG to JPG: Yes, often. If you have a PNG photograph (without transparency) and want to reduce file size for web use, converting to JPG makes sense. You'll save significant space with minimal visible quality difference.

JPG to PNG: Sometimes. Converting JPG to PNG does not improve quality — the JPEG artifacts are already baked in. However, it prevents further quality loss during editing, and it enables transparency support for the converted image.

The verdict

There's no single "better" format — it depends on the use case. A simple rule of thumb: use PNG for anything you create or edit, use JPG for anything you share or publish. For web images specifically, consider switching to WebP which offers the advantages of both formats with better compression than either.